Y9 Chemistry Revision

Question 1

Definition of an Element + eg

Answer 1

A substance made from only one atom e.g. gold

Question 2

Definition of a Mixture +eg

Answer 2

A substance made of two or more elemetns that are not chemically bonded
e.g. salt and water

Question 3

Definition of a compound +eg

Answer 3

A substance made of two or more elements that are chemically bonded
e.g. H20(water)

Question 4

Pure substance

Answer 4

they are substances that are not mixed with anything else e.g. diamond

Question 5

Solid +eg

Answer 5

Solids are fixed shapes with a fixed volume with closely packed particles that can vibrate and they are arranged in a structured pattern

Question 6

Liquid +eg

Answer 6

Liquids are particles that have a defined volume but no defined shape. They are loosely connected and can collide and move past one another. e.g. oil

Question 7

Gas + eg

Answer 7

Gases have no defined shape or volume, they have a lower density and force of attraction. The atoms move fast are are far apart e.g. air

Question 8

Atom definition

Answer 8

Atoms are the building blocks of matter and is the smallest unit of matter.

Question 9

Electron, Neutron, Proton

Answer 9

Negatively charged particle that orbits the nucleus
Neutrally charged particle found in the nucleus(centre) of an atom
Positively charged particle found in the nucleus(centre) of an atom

Question 10

Chemical vs Physical change +e.g.s

Answer 10

Chemical change is when a new substance is formed, this in irreversible as the atoms rearrange themselves eg cake
Physical change is when there is a change in the state(no new substance is made) e.g. ice melting

Question 11

Filtering

Answer 11

It is the process of separating two products by straining the liquid thought a sieve or filter

Question 12

Simple vs Fractional distillation

Answer 12

Simple distillation is used to separate two liquids that have a big difference in boiling points
Fractional Distillation is the same, except it contains a fractionating column as this method is only used to separate two liquids with a very close/ small difference in boiling points.

Question 13

Paper Chromatography

Answer 13

Chromatography is a separation technique in which the analysis of an unknown substance is carried out mainly by the flow of solvent a special filter paper.

Question 14

Solute

Answer 14

Substance that dissolves

Question 15

Solvent

Answer 15

The liquid where the solute dissolves in

Question 16

Soluble

Answer 16

Something that will dissolve