Y9 Chemistry

Particle theory & separating mixtures Atomic structure Structure and bonding – ionic bonding Periodic Table Metal reactivity, metal extraction and metallic bonding Structure and bonding – covalent bonding

What are the three states of matter?

Solid, liquid, gas

Arrangement of particles in a solid

Close together in a regular arrangement

Movement of particles in a solid

Vibrate about fixed positions

Energy of particles in a solid

Low

Arrangement of particles in a liquid

Close together but irregular

Movement of particles in a liquid

Move/slide past each other

Energy of particles in a liquid

Medium

Arrangement of particles in a gas

Far apart, random

Movement of particles in a gas

Rapid, random movement

Energy of particles in a gas

High

Define melting

Solid to liquid

Define freezing

Liquid to solid

Define boiling

Liquid to gas throughout

Define evaporation

Liquid to gas at surface

Define condensation

Gas to liquid

Define sublimation

Solid to gas without liquid

What happens to particle energy when melting?

Increases

What happens to particle arrangement when boiling?

Becomes far apart

Explain diffusion

Movement of particles from high to low concentration due to random motion

Why do gases diffuse faster than liquids?

Particles move faster and are further apart

Define solvent

The liquid that dissolves a substance

Define solute

The substance dissolved

Define solution

A solute dissolved in a solvent

Define saturated solution

A solution that cannot dissolve more solute

Define solubility

Maximum grams of solute dissolved in 100g solvent at a given temperature

What does a solubility curve show?

How solubility changes with temperature

What does a steeper curve mean?

Solubility increases rapidly with temperature

Define element

A substance made of one type of atom

Define compound

A substance of two or more elements chemically combined

Define mixture

Two or more substances not chemically combined

Property of pure substance

Fixed melting/boiling point

Property of mixture

Melting/boiling over a range

What is filtration used for?

Separating insoluble solid from liquid

What is crystallisation used for?

Obtaining dissolved solid

What is simple distillation used for

Separating solvent from solution

What is fractional distillation used for

Separating liquids with different boiling points

What is chromatography used for

Separating mixtures of soluble substances

What does a chromatogram show?

Number of substances in mixture

Define Rf value

Distance moved by substance / distance moved by solvent

Define atom

Smallest particle of an element

Define molecule

Two or more atoms covalently bonded

Subatomic particle with positive charge

Proton

Subatomic particle with no charge

Neutron

Subatomic particle with negative charge

Electron

Relative mass of proton

1

Relative mass of neutron

1

Relative mass of electron

1/1836

Relative charge of proton

+1

Relative charge of neutron

0

Relative charge of electron

-1

Define atomic number

Number of protons

Define mass number

Protons + neutrons

Define isotope

Atoms with same protons but different neutrons

Define relative atomic mass

Weighted average mass of isotopes

How to calculate Ar

(sum of isotope mass × abundance) ÷ total abundance

How are elements arranged in periodic table

By increasing atomic number

Define group

Vertical column

Define period

Horizontal row

What does group number tell you

Number of outer electrons

What does period number tell you

Number of electron shells

Electronic configuration of first 20 elements

Fill shells 2,8,8,…

Why do elements in same group react similarly

Same number of outer electrons

What is ionic bonding

Transfer of electrons forming oppositely charged ions

How are ions formed

Gain or loss of electrons

Group 1 ion charge

+1

Group 2 ion charge

+2

Group 3 ion charge

+3

Group 5 ion charge

-3

Group 6 ion charge

-2

Group 7 ion charge

-1

Silver ion

Ag+