C1

Question 1

What is the particle model

Answer 1

It explains how particles are arranged and how they move in solids, liquids and gases

Question 2

What is the different arrangements, distance and movement of particles in each state

Answer 2

Solid - regular, very close and vibrate around fixed positions
Liquid - random, close and move around each other
Gas - random, far apart and move quickly in all directions

Question 3

How does this explain properties of substances

Answer 3

You can’t compress a solid or liquid as there is no space for particles to move into. However you can compress a gas.
A particle in it’s solid state can’t flow and has a fixed shape as its particles vibrate around fixed positions and can’t move from place to place.

Question 4

What is a physical change

Answer 4

When a substance changed state or shape

Question 5

Characteristics of a physical change

Answer 5

No new substances are made
Reversible

Question 6

What is a chemical change

Answer 6

A change that produces one or more new substances

Question 7

Characteristics of a chemical change

Answer 7

The properties of the new substance formed is different from the properties of the original substances
new substance is formed

Question 8

What happens when a substance changes state

Answer 8

It’s particles stay the same but their arrangement and movement change

Question 9

What happens in a chemical change

Answer 9

The particles break up and join in different ways

Question 10

What is an atom and what is a molecule

Answer 10

Smallest particle of an element that still has it’s chemical properties
Molecule - two or more atoms joined together by chemical bonds

Question 11

Where are the subatomic particles found

Answer 11

Electrons - in shells around the nucleus
Protons and neutrons - in the nucleus

Question 12

What is the diameter and radius of the atom

Answer 12

62 x 10 to the -12 metres - diameter
31 x 10 to the -12 metres - radius

Question 13

What do particle models no take into account/show

Answer 13

The size of the particles
The forces between particles
The space between particles

Question 14

Relative mass and charge of the subatomic particles

Answer 14

1, +1 - proton
1, 0 - neutron
0.0005, -1 - electron

Question 15

What is an isotope

Answer 15

An atom with the same number of protons and electrons but with a different number of neutrons

Question 16

What does the mass number equal

Answer 16

mass number = number of protons + number of neutrons

Question 17

What is the atomic number

Answer 17

The number of protons / electrons

Question 18

What are ions

Answer 18

Ions are charged particles that form when atoms lose or gain electrons

Question 19

What did John Dalton think about matter

Answer 19

He thought that all matter is made from atoms. He thought of atoms as solid balls and all atoms of the same element were identical and therefore different elements have different atoms

Question 20

What did J.J Thompson discover

Answer 20

He discovered the electron. By finding out that a cathode ray changed direction in an electrical or magnetic field and that they were negatively charged particles.

Question 21

Plum pudding model

Answer 21

Made by J.J Thompson they have negatively charged electrons embedded in a positive mass - maintains the neutral charge of the atom.

Question 22

What did Rutherford and Geiger and Marsden discover

Answer 22

They discovered that there was a positively charged mass in the centre of the atom by shooting positively charged particles at the atom, they expected them to go through the foil but some changed direction and a few came straight back. they concluded there was a positively charged mass in the centre of the atom and the electrons orbited it.

Question 23

What did Niels Bohr discover

Answer 23

He used mathematical models and found out that the electrons are in fixed energy shells around the nucleus.