Chemistry P1

Anything that occupies space and has mass

Smallest unit of matter

Can be observed without changing the substance into something new; not changing its chemical formula

Colour, hardness, density, malleability, melting point

Solid, liquid, gas

When matter changes from one state to another

Fixed shape and volume

No definite shape

No designed shape or colume

How a substance behaves when it reacts to form a new substance; changing its chemical formula

Burning, toxicity, oxidation, etc

Matter that is only made up of one substance and cannot be physically separated into any other matter; elements and compounds

Elements - Can be found on the periodic table

ex)Helium, Hydrogen

Compounds - Found naturally, mix of elements together

Ex) H2O, NaCl

The physical mixing of 2 or more components; Homogenous and heterogenous

Homogenous - Looks like one substance

Ex) Soda, Orange juice

Heterogenous - You can see the physical components it is made of

Ex) Salad, trail mix

• The foundation of Atomic theory

• Atoms are spherical like billiard balls

• Each atom has its own unique properties

• Atoms are indivisible; they are the building blocks of life

• Atoms can combine in many ways to create a wide variety of elements/compounds

• Thomson discovers the electron

• The electron is 2000X smaller than the smallest atom and has a negative charge

• Atoms must contain electrons

• Electrons must be spread-out evenly throughout a positively charged atom like raisins in a bun

• Alpha particles from radioactive polonium were fired at a thin piece of gold foil

• Most alpha particles pass through the gold undeflected

• Atoms have a very small nucleus where almost all of the mass is located. Since the nucleus is so small, the alpha particles had a small chance of actually hitting it

• Rutherford discovered the nucleus was made up of protons and neutrons

• Electrons orbit the outside of the nucleus, like planets around the son. Most volume of an atom is empty space

• Electrons exist at certain distances from the nucleus(called orbits, shells, or energy levels)

• Max number for the 1st energy level = 2e-

• Max number for the 2nd and 3rd energy level = 8e-

• We can’t exactly know where an electron is at any given time, but electrons are more likely to be in specific areas

• E- are in a cloud

Made of atoms, atoms are made from subatomic particles

Charge - Negative

Mass - No mass

Symbol - e-

Location - Cloud, around the nucleus

Charge - positive

Mass - 1

Symbol - p/p+/H+

Location - In the nucleus

Charge - No charge, neutral

Mass - 1

Symbol - n

Location - In the nucleus

Electrons

Neutrons and protons

The # of protons and electrons in an element

The average weight of one element = protons and neutrons

When an electron is being added or taken away; an atom that has a positive or negative charge

• Because it doesn’t belong to a specific group

• It’s a non-metal that acts like a metal

Located to the left of the “staircase” and typically gives electrons

• Conductors of energy and heat

• Malleable

• Ductile

• Luster

Located to the right of the “staircase” and typically accepts electrons

• Poor conductors

• Brittle

• Not ductile

• Lack luster

Is considered the “staircase” which separates metals and non-metals and typically gives electrons

• The rows of elements from left to right.

• Total of 7 periods

• The row number is equivalent to the energy levels

• The rows of elements from up to down

• Total of 18 groups/families

• Groups is numerical while family is names

• The # of e- in the last energy level or valence e-, only works for g1-3, g13-18

It’s called the Alkali Metals and are very reactive with H2O(water)

It’s called the Alkaline Earth Metals and are less reactive with H2O(water)

It’s called the Halogens and are very reactive non-metals

It’s called the Noble Gases and are non-reactive

Elements that are paired when alone'

H O N Cl Br I F

Sulfur has 8 and phosphorus has 4

The electrons in the outermost shell of an atom

• How many valence e- are in the last energy level

• Tells us the reaction behavior of the atom; whether an atom is going to give or take e-

By gaining or losing e-

• Bond between non-metal and metal

• Transfer electrons

• Solid at room temp

• Can conduct in solutions as long as they can dissolve in water

• Bond between non-metal and non-metal

• Share electrons

• Solid, liquid, and gas at room temp

• Low to no conductivity in solutions

They indicate the number of particular type of atom in the chemical formula for a molecule or a compound

Coefficients appear in front of a compound formula to indicate how many compounds of that type are

• High melting point

• Retain their crystal shape

• Vary in solubility

• Are conductors when they dissolve in solutions. Ionic compounds that do dissolve and conduct electricity are called electrolytes

• Form 3D grids called lattices

International committee of pure and applied chemist