C1 Atomic Structure

Question 1

What are all substances made of?

Answer 1

Atoms

Question 2

What is an element?

Answer 2

A substance that is made of only one type of atom

Question 3

What is a compound?

Answer 3

A substance made of more than one element

Question 4

What is the law of conservation of mass?

Answer 4

Total mass of reactants = total mass of products

Question 5

What is a mixture?

Answer 5

Two or more substances that are not chemically combined together

Question 6

Give three ways to separate mixtures

Answer 6

Filtration, crystallisation and distillation

Question 7

What is filtration?

Answer 7

When you separate substances insoluble in a solvent from those that are soluble in the solvent. Like sand from salt

Question 8

What is crystallisation?

Answer 8

When you separate a soluble solid from a solvent. Like salt from salt solution

Question 9

What is distillation?

Answer 9

When you separate a solvent from soluble solids dissolved in the solvent. Like seawater distilled to obtain usable water

Question 10

What is fractional distillation?

Answer 10

A way to separate mixtures of miscible liquids. Like water and ethanol

Question 11

What does miscible mean?

Answer 11

When a liquid completely dissolves in another liquid

Question 12

How does fractional distillation work?

Answer 12

The liquids have different boiling points and when the mixture is heated the liquid with the lower boiling is able to be collected first

Question 13

What is paper chromatography?

Answer 13

A way to separate substances from mixtures in a solution

Question 14

Why does paper chromatography work?

Answer 14

Because some compounds are more soluble than others in the solvent

Question 15

What did Dalton suggest about atoms in the early 1800s?

Answer 15

That they were tiny hard spheres

Question 16

What did Thomson discover at the end of the 1800s

Answer 16

A negatively charged particle called the electron

Question 17

Who proposed the plum pudding model and what did it suggest?

Answer 17

It was proposed by Thomson and it suggested that negative electrons were embedded in a ball of positive charge

Question 18

Who conducted the gold foil experiment and what did it prove?

Answer 18

It was conducted by Geiger and Marsden and it they proved that there was a tiny spot of positive charge in the centre of the atom by firing alpha particles at a thin piece of gold foil

Question 19

Who proposed the nuclear model and what was it?

Answer 19

It was proposed by Rutherford and it was electrons orbiting around a nucleus which contained positively charged protons

Question 20

What did Bohr suggest?

Answer 20

That electrons were orbiting the nucleus in energy levels

Question 21

What did Chadwick prove the existence of?

Answer 21

Uncharged particles called neutrons in the nucleus

Question 22

What are atoms made of?

Answer 22

Protons, neutrons and electrons

Question 23

How do you find atomic number?

Answer 23

Number of protons (=number of electrons)

Question 24

How do you find mass number?

Answer 24

Number of protons + number of neutrons

Question 25

What is an ion?

Answer 25

A charged atom

Question 26

What is an isotope?

Answer 26

Atoms of the same element with different numbers of neutrons - they have identical chemicals properties but their physical properties can differ