The less energy required to remove an electron, the more energy it will have after ejection.
The valence electrons are in the lowest level of energy.
The ion has more electrons than the neutral atom.
The electrons will push each other away.
The atomic size decreases as you move across a period.
The element Z will have the highest electronegativity value because it is farthest to the right.
Both chlorine and argon's first valence electrons are in the third energy level.
It exerts a higher nuclear charge on the electrons because it has the highest number of protons out of all the options.
The electron configuration is shown in the ground state of neutral sodium.
The positively charged ion has the same electron configuration as neon.
When you move from left to right across the periodic table, you add protons to the nucleus, which increases the pull of each nucleus on its electrons.
It will have a larger first ionization energy, greater electronegativity, and a smaller atomic radius.
The more distant the electron is from the nucleus, the less ionization energy it needs to be removed.
The atomic mass is the sum of the two elements in an atom's nucleus.
We can find the number of neutrons by subtracting the atomic number from the weight.
The 11B has only 1 in excess of the atomic number of B.
The number of Cl is 17 and it has 20 neutrons and 3 in excess.
24Mg has the same number of neutrons as protons because of the atomic number of 12.
There are 39 neutrons in the nucleus of the element Ga.
Mass spectrometry can be used to determine the mass of an element.
Each element has more than one possible mass through mass spectrometry.
Nonmetals are smaller than the other elements on the periodic table.
They have higher electronegativity values because it is easier for them to attract additional electrons.
When an electron is removed from a full shell, the ionized energy will show a big jump.
The element is stable after two electrons are removed because of the jump between the second and third electrons.
The only element with two electrons is magnesium.
4.5 eV 19 is the radiation energy.
As the binding energy of the electron wouldn't change, the excess radiation energy would turn into energy that increases the electron's speed.
The amount of energy that the light has does not affect the intensity of the light.
The amount of radiation energy is not affected by the brightness of the light.
The amount of energy in the ejected electrons would not change.
Microwave radiation can be used to determine the shape of full molecule.
When forming an ion,electrons are first.
The electrons will remain unpaired as long as there are empty orbitals for them to enter.
The goal is to make the base metal stronger.
The metals from which they are created have less malleability than the metals from which they are created.
It is easier to remove the outermost electron in Ca because it is more shielded from the nucleus.
The second ionization energy will be larger than the first but still comparable because both electrons are being removed from the same energy level.
The third electron is harder to remove than the other two because it is being removed from a lower energy level.
All peaks are the same height.
The mass of chlorine must be 51 amu-16 amu.
The mass number is equal to the number of protons and neutrons in chlorine.
The mass of an atom is made up of only two particles: neutrons and protons.
Changing the number of electrons doesn't change the mass very much.
Oxygen is more attracted to the electrons in the bond than chlorine.
chlorine and phosphorus have three energy levels with electrons present, so they have the largest atomic radii.
The nuclear charge of chlorine is higher than that of phosphorus.
The smaller size and greater number of protons of chlorine makes it have a higher ionization energy.
The number of peaks represented by the rightmost peak is the same as the number of peaks represented by the chlorine atom.
Write out the full electron configuration of the most likely element in the photoelectron spectrum.
The different energy levels of the electrons are represented by the different areas of ionization energy.
The closer the electrons are to the nucleus, the more energy will be required to remove them.
There are three different areas for the peaks of sulfur.
There are subshells which are not the same distance from the nucleus.
The peaks have a ratio of electrons present in them.
Bonding and Phases are chemical and physical properties of materials and can be explained by the structure and arrangement of atoms.
In order to reach a more stable, lowerenergy state, atoms engage in chemical reactions.
The most stable elements are those that have eight electrons in their shells.
As a result, atoms with too many or too few electrons in their valence shells will find one another and pass the electrons around until all the atoms in the molecule have stable outer shells.
An ionic bond can be formed when an atom gives up electrons completely.
Some atoms form bonds with each other.
An ionic solid is held together by the attraction of the two ion's next to one another in a lattice structure.
They happen between metals and nonmetals.
electrons are not shared The anion gets an electron from the cation.
The two ionized bonds are held together by the forces of nature.
A chlorine atom has seven valence electrons and uses them to complete its outer shell, as shown in the diagram below.
Positive and negative charges on the ion hold the two atoms together.
Any substance that is held together by ionic bonds will usually be a solid at room temperature and have high melting and boiling points.
The melting points of ionic substances are affected by two factors.
The charge is the main factor.
A compound with a higher melting point than a compound with a lower melting point is called a lattice energy compound.
The size of the ion must be considered if both compounds are made up of the same ion.
A substance like LiF would have a greater melting point if it were smaller.
In an ionic solid, each electron is 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- The electrons are still in the liquid phase of the ion, but they are free to move about in the liquid phase.
Salts are held together by bonds.
The sea of electrons model can be used to examine metals.
The positively-charged core of a metal, consisting of its nucleus and core electrons, is generally stationary, while the valence electrons on each atom do not belong to a specific atom and are very mobile.
Mobile electrons explain why metals are good conductors.
The delocalized structure of a metal explains why metals are both flexible and rigid.
It is possible for metals to bond with each other.
When two metals are melted into their liquid phases, they are poured together before cooling and creating the alloy.
The iron atoms occupy the interstices of the smaller carbon atoms.
Some copper atoms are replaced with zinc atoms to create brass.
The shared electrons are counted as part of the atom's shell.
Both atoms achieve complete outer shells in this way.
Two fluorine atoms, each of which has seven electrons and needs one electron to complete its valence shell, form a bond in the diagram below.
Each atom donates an electron to the bond, which is considered to be part of the valence shell of both atoms.
The number of bonds an atom can make is the same as the number of unpaired electrons.
The first bond formed between two atoms is called a sigma bond.
sigma bonds are all single bonds.
If there are more bonds between the two atoms, they are called pi bonds.
The second and third bonds in a triple bond are also pi bonds.
Double and triple bonds are not twice or triple the strength as single bonds.
A single bond has one sigma bond and one bond order.
The longest bond is the single bond.
atoms are held together in a lattice of bonds in a network solid You can see a network solid as a molecule.
Network Solids are very hard and have high melting and boiling points.
The electrons in a network solid can't move about the lattice because of the bonds between their atoms.
Poor conductors of electricity are made by this.
The compounds of carbon and SiO2 are the most common network solids.
Carbon and Silicon have four valence electrons, which means they can form a large number of bonds.
When Silicon is doped with other elements, it becomes a Semiconductor.
Each individual Silicon atom is joined to four other Silicon atoms in a normal lattice.
The neighboring Silicon atoms will lack one bond when they are replaced with elements with only three electrons.
The missing bond creates a positive charge in the lattice and the hole attracts other electrons to it.
The electrons leave behind holes when they move, creating a chain reaction in which the Silicon's conductivity increases.
If an element with five valence electrons is used to add impurities to a Silicon lattice, there is an extra valence electron that is free to move around the lattice, causing an overall negative charge.
In the F2 molecule shown on this page, the two fluorine atoms share the electrons equally, but that's not usually the case in molecules.
If one of the atoms exerts a stronger pull on the electrons in the bond, it will keep the electrons on one side of the molecule more than on the other side.
The molecule has a dipole moment.
The side of the molecule where the electrons spend more time will be negative and the side of the molecule where the electrons spend less time will be positive.
Oxygen has a higher electronegativity than hydrogen and thus will have the electrons closer to it.
The oxygen and hydrogen have positive and negative dipoles.
The dipole moment is used to measure the polarity of a molecule.
The bigger the dipole moment is, the more polar the molecule is.
You don't need to calculate the strength of a dipole, but you should know the unit with which that strength is quantified.
The unit is called the debye.
Intermolecular forces are the forces that exist between the two bonds of a molecule.
These forces need to be broken apart in order for covalent substances to change phases.
The bonds between the individual ion are broken when ionic substances change phase.
The bonds between the individual atoms remain in place when covalent substances change phase.
The positive end of one polar molecule is attracted to the negative end of another polar molecule.
Molecules with larger dipole moments tend to have higher melting and boiling points.
Dipole-dipole attractions are weak and melt and boil at very low temperatures.
Liquids and gases are held together at room temperature.
A special type of attraction is hydrogen bonds.
In a hydrogen bond, the positively charged hydrogen end of a molecule is attracted to the negatively charged end of another molecule.
When a hydrogen atom gives up its lone electron to a bond, it leaves its positively charged nucleus unshielded.
Water and ammonia have higher melting and boiling points than other substances that are held together only by other types of intermolecular forces.
Water is less dense as a solid than as a liquid because of the hydrogen bonds that make icecrystals.
The London dispersion forces are caused by all the molecules.
The weak attractions are caused by the random motions of electrons.
A nonpolar molecule might have more electrons on one side than on the other at a given moment.
The molecule will act as a weak dipole.
Molecules with more electrons will experience greater London dispersion forces.
Among substances that only experience London dispersion forces, the one with more electrons will have higher melting and boiling points.
Substances that experience only London dispersion forces melt and boil at extremely low temperatures, and tend to be gases at room temperature.
The dispersion forces between Molecules and London start to become more significant as Molecules gain more electrons.
It is difficult to compare the boiling point of a nonpolar substance with that of a polar substance.
Water has hydrogen bonds and a boiling point.
While butane's boiling point is 34degC, octane's is 125degC.
Even though octane has no permanent dipoles, it has so many electrons that its London dispersion forces are significant enough that they create greater intermolecular attractions than even the hydrogen bonds in water.
The role of London dispersion forces is determined by the mass of the molecule.
The strength of the IMFs is not affected by the mass.
As mass increases, so does the number of electrons, as the molecule must remain neutral.
It is much easier to compare the strengths of the same molecule in the AP Exam than it is in the real world.
It's worth keeping in mind that London dispersion forces can have an impact on the trends of the International Monetary Fund.
The bonds holding the lattice together are broken when ion substances are turned into liquids.
The amount of energy needed for that is determined by the Coulombic attraction between the molecules.
When the intermolecular forces between them are broken, covalent substances will boil.
The relative strength of the IMFs within the molecule can be determined by the following ranking.
Non-hydrogen bond permanent dipoles.
The bigger the molecule, the stronger the London dispersion forces because they have more electrons.
The melting and boiling points of covalent substances are usually lower than the melting and boiling points of ionic substances.
Transition metals tend to have high melting points due to the fact that metallic bonding only involves one type of atom.
Network covalent bonding is the strongest type of bonding there is, and it is very difficult to cause it to melt.
The strength of the intermolecular forces is related to the phase of a substance.
Solids have highly ordered structures where the atoms are packed tightly together, while gases have atoms spread so far apart that most of the volume is free space.
Substances with weak intermolecular forces tend to be gases at room temperature.
Nitrogen is an example of this.
Substances with strong intermolecular forces are liquids at room temperature.
Water is a good example.
Intermolecular forces are not experienced by ionized substances.
Their phase is determined by the ionic bond.
Ionic substances are usually solid at room temperatures because they are stronger than intermolecular forces.
The relative strength of the intermolecular forces in a substance can be used to predict several other properties of that substance.
Vapor pressure is the most important.
Vapor pressure is caused by the fact that the liquid is moving.
If those molecules hit the surface of the liquid with enough energy, they can escape the intermolecular forces holding them to the other molecule and transition into the gas phase.
Vaporization is a process.
A liquid boiling is not the same as a liquid boiling.
When a liquid is boiled, the energy in the form of heat increases until all of the intermolecular forces are broken.
No outside energy is needed for vaporization to occur.
There is a direct relationship between temperature and pressure.
The higher the temperature of a liquid, the faster the molecule are moving and the more likely they are to break free of the other molecule.
The temperature and vapor pressure are related.
The strength of the intermolecular forces within the liquid is the most important factor in determining the vapor pressure.
The higher the intermolecular forces are, the less likely the molecule will escape the liquid.
When you take the test, you will be asked to draw the Lewis structure for a molecule or polyatomic ion.
Refer to this page for the periodic table to count the valence electrons in the molecule or polyatomic ion.
If a polyatomic ion has a negative charge, add electrons to the total.
If a polyatomic ion has a positive charge, subtract the electrons from the total.
Place two electrons between the bonds of each pair of atoms after drawing the molecule's skeleton.
The central position of the molecule is usually occupied by the least negative atom.
Attach electrons to the surrounding atoms.
The electrons should be added to the central atom.
Until the central atom has an octet, do this.
The Lewis dot structure is needed for the ion.
Oxygen has 6 valence electrons while carbon has 4.
Add 2 electrons to the ion because it has a charge of -2
The central atom is carbon.
There's nothing left to put on the carbon atom because we've added all 24 electrons.
Add a charge of negative two to the model by placing a bracket around it.
When we put a double bond into the ion, we place it on all of the oxygen atoms.
The strength and lengths of all three bonds are the same as a single bond and a double bond.
A bond order calculation can be used to determine the relative length and strength of a bond.
A single bond has an order of 1 while a double bond has an order of 2.
Pick one of the bonds in the resonance structure and add up the total bond order across the resonance forms, then divide that sum by the number of resonance forms.
The top C-O bond would have a bond order of 1.33.
The strength and length of resonance bonds can be compared using bond order.
The bonds of a compound that displays resonance are all the same, despite the way the Lewis diagrams have been drawn.
It looks like a mix of single and double bonds because any attempt to show a bond between the two strengths would be awkward.
Some atoms have less than eight electrons in their outer shell.
Both hydrogen and helium require two electrons.
The diagram below shows that Boron is stable with six electrons.
The minimum number of electrons required to be stable is eight.
Here are a few examples.
Sometimes there is more than one valid Lewis structure.
CO2 has two structures that are valid as shown below.
Formal charge is used to determine the structure.
To calculate the formal charge on atoms in a molecule, take the number of valence electrons for that atom and subtract the number of assigned electrons in the Lewis structure.
The lone pairs and bonds count as two and one, respectively, when counting assigned electrons.
The neutral molecule's formal charge should be zero on both diagrams.
The more atoms there are with a formal charge, the more likely the structure will be.
The overall charge on the ion should be equal to the formal charges on each atom.
When atoms come together to form a molecule, they assume the shape that keeps their different electron pairs apart.
The shape of the molecule is determined by the number of electron pairs on the central atom.
The standard shape is affected by the number of bonding pairs and lone pairs of electrons on the central atom.
You should remember some things when dealing with the model.
Double and triple bonds are the same as single bonds in terms of predicting overall geometry for a molecule; however, multiple bonds have slightly more repulsive strength and will occupy a little more space than single bonds.
Bond angles between terminal atoms will be slightly reduced with lone electron pairs because of their repulsive strength.
The pages show the different geometries that you can see on the test.
The angle between the terminal atoms in the bent shape is less than 120 degrees.
The angle between the terminal atoms in the trigonal pyramidal and bent shapes is less than it should be.
In trigonal bipyrimidal shapes, place the lone pairs first.
The average kinetic energy of the gas is related to the temperature of the gas.
All the gases in the sample will have the same average energy.
The average energy of a gas depends on the absolute temperature, not the identity of the gas.
The volume of an ideal gas particle is insignificant when compared with the volume in which the gas is contained.
There is no attraction between the gas molecules.
There is no loss of energy when gas molecules collide with one another and with the walls of a container.
The range of velocities is shown in a diagram.
Molecules are moving at different speeds at a given temperature.
When determining the temperature, we take the average velocity of all the molecules and use that in the equation to calculate it.
Unless you are taking AP physics, you don't need to know that equation.
All you need to know is that temperature is related to energy.
The first type of diagram involves plots of the velocities of gas at different temperatures.
There are three curves representing a sample of nitrogen gas at 100 K, 300 K, and 500 K.
The larger the range is for the individual molecule, the hotter the gas is.
The increased KE is due to the increased velocity of the gas molecule, as all the molecules in this example have the same mass.
A number of gases are shown in a number of diagrams.
All of the gases have the same amount of energy because they have the same temperature.
Some atoms have the same mass.
If the atoms have smaller mass, they must have greater velocities in order to have the same energy as larger mass atoms.
They have the highest average velocity because they have the least mass.
The lower the mass, the lower the velocity.
A gas escapes from a container through tiny holes in the container's surface.
Even though the rubber or latex that makes up a balloon may seem solid, it will gradually shrink over time.
There are tiny holes in the balloon's surface that allow gas to escape.
The speed of the gas particles is what determines the rate at which a gas effuses from a container.
The faster the particles are moving, the more likely they are to hit the sides of the container and escape.
If examining gases at the same temperature, the gas with the lower mass will effuse first, because the rate of effusion increases with temperature.
If you have experienced this, you know that a balloon filled with helium will deflate more rapidly than a balloon filled with air or carbon dioxide.
The formula that quantifies the rate at which a gas will effuse is beyond the scope of the exam.
If you understand the basic principles behind effusion, you should be able to answer any questions that come up.
If you already know the other three variables, you can use the ideal gas equation to calculate them.
The ideal gas equation can be used to figure out how changes in each of its variables affect the other variables.
The Combined Gas Law only works when the number of moles is constant.
As pressure increases, temperature increases, and as temperature increases, pressure increases.
As pressure increases, volume decreases; as pressure decreases, volume increases.
That's the law.
As temperature increases, volume increases; as volume decreases, temperature increases.
That's Charles's Law.
The total pressure of a mixture of gases is the sum of the individual pressures of the gases in the mixture.
The partial pressure of a gas is proportional to the number of moles in the mixture.
If 25 percent of the gas in a mixture is helium, the partial pressure will be 25 percent of the total pressure.
Gases behave in a less than ideal way at high pressure and low temperature.
Under these conditions, the assumptions made in the theory become invalid.
There are two things that happen when gas is packed tightly.
The volume of a gas under nonideal conditions will be larger than the volume predicted by the ideal gas equation.
The ideal gas equation assumes that gas doesn't stick together.
Intermolecular forces cause gas molecule to stick together when a gas is packed tightly.
The pressure in a nonideal situation will be smaller than the pressure predicted by the ideal gas equation because there are fewer particles bouncing around.
Gases will show some deviation from ideal behavior even under normal conditions.
When considering the likelihood that a gas will deviate from ideal behavior, stronger IMFs will lead to more deviations.
H2O would be more likely to deviate from ideal behavior than CH4.
The more polarizable a gas is, the more likely it is to deviate from ideal behavior.
The noble gases, which have only LDFs, are more likely to deviate from ideal behavior than other gases.
You might be asked about the density of gas.
The density of a gas is the same as the density of a liquid or solid: in mass per unit of volume.
Combining the density equation with the ideal gas law can be used to determine the density of a gas sample.
Mass per mole is how MM is measured.
There is a rule for remembering which solutes are dissolved in which solvent.
That means that polar or ionic solutes can be dissolved in water.
Nonpolar solutes are best dissolved in nonpolar solvent.
When an ionic substance breaks up, it's called an ion.
The free ion in a solution can conduct electricity.
The greater the amount of ion present in an ionic compound, the better it will be.
A solution of magnesium chloride will have one Mg2+ and two Cl-.
A solution of sodium chloride will have a neutral composition.
If both solutions have the same concentrations, a solution of magnesium chloride will conduct electricity better than a solution of sodium chloride.
Intermolecular forces and Coulombic attractions can be used to separate substances from each other.
There are many ways to do this.
There are many types of chromatography.
Paper is the medium through which the solution passes.
Many chemical solutions, such as the ink found in most pens, are a mixture of a number of covalent substances.
Each of these substances has a different affinity depending on the solvent.
The separation of pigments in black ink is one of the most common paper chromatography experiments.
Black ink is usually made up of substances of several different colors.
In paper chromatography, a piece of filter paper is suspended above a solvent so that the bottom of the paper is touching the solvent.
There is a line at the bottom of the filter paper that starts out above the solvent level.
The various substances inside the ink will be attracted to the polar water.
The more polar the substance is, the more attracted it will be to the water.
The ink on that strip was made of three different substances.
The one that traveled furthest with the water had the strongest attractions and was the most polar, whereas the one that didn't travel very far from the starting line was the least polar.
In the above example, ink is used because paper chromatography is the most useful with colored substances.
One limitation of paper chromatography is that components of the ink that have no visible color can't be seen on the filter paper.
Water is not the only solvent that can be used.
There are many nonpolar solvents that can be used.
In the case of a nonpolar solvent, the position of the various ink components in the above diagram would have been reversed.
Column chromatography is a type of chromatography.
A column is packed with something.
The solution to be separated is injected into the column where it sticks to the stationary phase.
The eluent is injected into the column after that.
As the eluent passes through the stationary phase, the analyte molecule will be attracted to it with different degrees of strength.
The more attracted certain analyte molecules are to the eluent, the faster they will leave the column.
If there is a sufficient polarity difference between the components, substances will leave the column at different times, allowing them to be separated.
A variety of methods can be used to analyze the eluted mixture.
Liquids or gases can be used as the eluent in column chromatography.
Distilling solutions is a third method.
Distillation takes advantage of the different boiling points of substances to separate them.
The water in the mixture will not boil if you heat it to 85 degrees.
A piece of glassware is a smaller tube running through a larger tube.
The larger tube has hose connections that allow water to run through it.
This cools the inner tube and not the outer tube.
When run through the inner tube, the Ethanol Vapor will cool and condense into a liquid form, which can be collected on the other side of the condenser.
The solutions don't need to be colored to separate them.
Keeping the flask at a constant temperature can be a challenge, which is why the temperature must be monitored closely to ensure that you are only boiling one component of the mixture at a time.
It can't be used to separate a mixture with unknown boiling points.
Network covalent bonding is the strongest type of bonding.
CaF2 requires a lot of energy to break up an ionic lattice.
Nitrogen cannot be a terminal atom in this molecule because it is larger than bromide.
It is not possible to complete the octets for all six atoms.
Nitrogen doesn't have enough electronegativity to be the central atom of the molecule.
The following information can be used to answer questions.
There is a container filled with hydrogen and neon.
The pressure inside the container is 1.0 atm and the temperature of the gases is 0.
A sample of liquid NH3 is boiling.
As the NH3 molecule speed up, the temperature of the solution increases.
The amount of energy within the system is constant.
Lewis structures of four different molecules are shown in the diagrams.
There are three single bonds and three double bonds in the benzene molecule.
The following information can be used to answer questions.
All three gases are present at the same temperature.
There is a total pressure of 1.2 atm.
Nitrogen gas was collected.
A 22.0 gram sample of an unknown gas is 11 liters in size.
There are diagrams for nitrate and nitrite.
The relationship between the two ion is described in terms of bond length and bond energy.
The bonds of nitrate and nitrite are different.
The bonds of nitrate and nitrite are different.
The bonds of nitrate and nitrite are different.
A gas sample with a mass of 10 grams occupies 5 liters and has a pressure of 2.0 atm.
Lewis diagrams can be used to answer questions.
The substances are kept in the same containers.
All three substances have the same boiling points.
All three substances have the same number of electrons.
The three substances would be in water because of their permanent dipoles.
The following information can be used to answer questions.
There are several different Lewis diagrams for the sulfate ion.
The molecule represented by structure A is more polar than it is.
The bonds in the molecule are not as strong as those in structure A.
The bonds in the molecule are the same.
The following information can be used to answer questions.
The diagram shows three identical 1.0 L containers filled with gas.
The stopcocks connecting the containers are not open.
The gases exert the same amount of pressure.
The stopcocks are open.
There is a mixture of two liquids in the Erlenmeyer flask.
The mixture starts to boil when the flask is attached to the distillation apparatus.
You should justify your answer in terms of the funds.
The carbonate ion is formed when carbon dioxide reacts with cold water.
If they apply, include resonance forms.
A student has a mixture.
The mixture is heated until it begins to boil.
Justify your answer.
The graph shows the changes in pressure when the temperature of the gas is changed.
Justify your answer.
The water has a mercury content of 30.0 millimeters.
Equal quantities of O2 and H2O are held in a closed vessel.
A student performs an experiment in which a butane lighter is held underwater under a graduated cylinder which has been filled with water as shown in the diagram below.
Butane gas is released when the switch on the lighter is pressed.