1. ELEMENTS OF LIFE

Linear 180° e.g. BeCl2

Trigonal Planar 120° e.g. BF3

Bent 118° e.g. NO2

Tetrahedral 109.5° e.g. CH4

Pyramid 107° e.g. NH4

Bent 104.5° e.g. H2O

Trigonal Bipyramid 120°,90° e.g. PCl5

Octahedral 90° e.g. SF6

That all atoms are SPHERES and all elements are made from different spheres

In 1897 J.J Thompson discovered the electron and said there were negative electrons "plums" in a positive "pudding"

1909, Ernest Rutherford. Fired positive alpha particles at gold leaf. Most went through to other side, some deflected back. Very few deflected directly back. He concluded that the atom had a very small positively charged nucleus and a negative cloud of empty space.

1913, Niels Bohr. Found a problem with previous model (electrons would collapse into positive nucleus). He fired heat energy at atoms. The energy is absorbed by electrons and they move up an energy level and emit Em radiation when they drop back down. The photon given out is directly proportional to the frequency. E=hv. energy levels are quantised.

-2 nuclei fuse together to make a heavier molecule -happens in the sun and other stars -needs VERY HIGH TEMPERATURES AND PRESSURES to overcome repulsive forces. E.g. H+H -> He

1 orbital, can hold 2 electrons

3 orbitals, can hold 6 electrons

5 orbitals, can hold 10 electrons

7 orbitals, can hold 14 electrons

When 2 electrons occupy 1 orbital they 'spin' in opposite directions

Spherical

Px, Py and Pz

1 is the energy level (period) s is the orbital type 2 is the number of electrons in orbital

1s^2 2s^2 2p^6 3s^2 3p^6 3d^6 4s^2

Oppositely charged ions held together by electrostatic attractions

OH -

NH4 +

CO3 2-

NO3 -

SO4 2-

Regular structure, cubic shape and giant repeating pattern. e.g. sodium chloride

-high melting and boiling point ( because strong electrostatic attractions between ions) -most are soluble in water (because water molecules are polar and can attract ions to break up the structure) -hard and brittle e.g. Lithium hydroxide

Shared pair(s) of electrons

-low melting and boiling points ( because strong forces between atoms but weak forces between molecules) -soft and flexible (normally) -don't conduct electricity when dissolved in water e.g. ethanol, CO2, methane (CH4)

-giant covalent structure -each carbon is bonded to four other carbon atoms -high melting point -doesn't conduct electricity -insoluble -very hard

-giant covalent structure -each carbon is bonded to three other carbon atoms, in layers -high melting point -soft, slippery, used in locks and pencils -conducts electricity ( has delocalised electrons) -insoluble -used in pencils and as a lubricant

-giant covalent structure -same as diamond but one oxygen between each silicon bond -high melting point -hard -doesn't conduct electricity -insoluble

Giant lattice structure of positive ions in a sea of delocalised electrons

-high melting and boiling points (except for group 1 metals because they have large atoms and don't form as many bonds) -conduct electricity (because delocalised electrons can carry a charge) -conduct heat -malleable and ductile -insoluble

When an atom becomes excited (absorbs energy) it moves up to a higher energy level and when it eventually comes back down it emits extra energy as EM and gives off an emission spectrum

Shows the frequency of light given out when an electron moves down energy levels. Appear as coloured lines on a black background.

-EM radiation passed through an element in a gaseous state. -Appear as black lines on a colourful background. -Shows the missing frequencies from an otherwise continuous spectrum. -Can be used to detect the presence of hydrogen and helium in stars.

The shell closest to the nucleus

... they produce a series of lines in the ultra violet part of the spectrum

... they produce a series of lines in the visible part of the spectrum

... they produce lines in the infrared part of the spectrum

Speed of light (3x10^8) / wavelength (m)

Planck's constant (6.63x 10^-34 JHz^-1) x frequency (Hz)

1. Dip nichrome wire into hydrochloric acid

2. Dip into solid sample

3. Place in blue Bunsen flame and observe colour (Alternatively, can use liquid samples)

crimson red

Yellow/orange

Lilac

Brick red

Apple green

Blue green

1. Vaporisation 2.Ionisation 3.Acceleration 4.Ion drift 5.Detection

have the same number of protons but a different number of neutrons

6.02 x 10^23 Avogadro's constant (given exam)

Avogadro's number x number of moles

mass/ Mr or concentration (mol dm^3) x volume (dm^3)

Mr x moles

1. Write out equation

2. Make into ions

3. Cancel out ions that appear on both sides 3.Write out ionic equation

ions that don't get involved in the reaction

the smallest whole number ratio of elements in a compound

1. Write out elements involved

2. Write out masses or the percentages as masses (e.g. 77.5% = 77.5g)

3. Divide these by relative atomic mass to find the number of moles

4. Divide all numbers by the smallest number of moles

5. Write out the compound e.g. C4H8

1. Write out two molecules involved

2. Write out the masses of each molecule

3. Divide these b the relative molecular mass to get moles

4. Divide all numbers by the smallest number of moles

actual yield/ theoretical yield x 100

1. Weigh out solid precisely

2. Transfer it to a beaker and wash out any solid left behind

3. Stir the solid to dissolve 4.Use a funnel to transfer it to a volumetric flask, rinse to make sure all solid is transferrred 5.Use a pipette to fill up with water up to graduation line

4. Invert a few times to mix it

final concentration/ initial concentration x volume required

-used to find concentration -put acid or alkali in burette with known concentration -use pipette to measure acid or alkali and out in conical flask -add drop by drop until colour changes (the endpoint) -read from burette the amount of acid / alkali used. read at eye level from bottom of miniscus. record to two decimal places -repeat until concordant results (0.1cm^3 away from each other

Turns: acid- colourless alkali- pink

Turns: acid- yellow alkali- red

Write out BALANCED equation ratio conc vol moles ^put in all values and find moles (moles= conc x volume) multiply using the ratio to find the moles of the other

divide by 1000

-columns -have similar properties -same number of electrons on outer shell

-rows -have the same number of electron shells

-generally increase as metal ions have increasing positive charge, increasing number of delocalised electrons and smaller ionic radius so have a stronger metallic bond -silicon has very high because giant covalent structure -phosphorus has a lower melting point because it has a simple molecular structure -sulphur has a larger simple molecular structure than phosphorous so higher melting point -chlorine is even lower because it has a simple molecular structure -Argon has very low melting point because only exists as individual atoms

the minimum amount of energy required to remove 1 mole of electrons form one mole of atoms in a gaseous state

endothermic, requires energy, has a positive value

it decreases, because shielding increases

it increases, because increasing number of protons means there's increasing nuclear attraction and more energy is needed to remove the outer electron

= metal hydroxide+ hydrogen

=metal oxide

When they burn in oxygen white solids are formed

Bases, group 2 oxide + water → metal hydroxide, the hydroxide ions devolve and ionise in the water, producing strongly alkaline solution

EXCEPTION : MgO only reacts slowly with water and the hydroxide isn't very soluble

reactivity increases down the group because the hydroxide gets more soluble

thermal stability increases down group

solubility DECREASES down the group

solubility INCREASES down the group

positive think: cats are pawsitive :)

negative think: onions are bad :(

all: Potassium Lithium Ammonium Nitrates Sodium are soluble. think: PLANS

most are soluble except: silver halides, copper iodide (white), lead chloride, lead bromide(white) and lead iodide (yellow)

only: Sodium Calcium Ammonium Lithium Potassium Strontium and barium hydroxides are soluble think: SCALPS

Potassium Ammonium Lithium Sodium are soluble, think: PALS

Most carbonates aren't soluble -copper carbonate is blue/green -silver carbonate is yellow -most other carbonates are white

precipitation reactions 2 soluble salts -> insoluble salt + soluble salt

acid + metal(or insoluble base e.g. metal oxide/hydroxide)

acid + alkali

1. add metal/metal oxide/metal hydroxide to acid

1. Filter

2. Rinse with deionised water

3. Dry