Unit 1: Fundamental Particles

Question 1

Define atom

Answer 1

The smallest part of an element that can still be recognised as that element

Question 2

Define element

Answer 2

A substance made of only one type of atom

Question 3

Define compound

Answer 3

A substance made of more than one atom chemically bonded together (can be atoms of the same type!)

Question 4

Define molecule

Answer 4

A substance made of more than one atom chemically bonded together (can be atoms of the same type!)

Question 5

Define mixture

Answer 5

A substance made of more than one thing not chemically bonded together

Question 6

State the three subatomic particles

Answer 6

Protons, neutrons, electrons

Question 7

State the masses of the subatomic particles

Answer 7

Protons: 1, neutrons: 1, electrons: Very Small

Question 8

State the relative charges of the subatomic particles

Answer 8

Protons: +1, neutrons: 0, electrons: -1

Question 9

How are the subatomic particles arranged in an atom? (3 marks)

Answer 9

Protons and neutrons in the nucleus, electrons orbiting in shells

Question 10

What is the plum pudding model of the atom?

Answer 10

A ball of positive charge with negative electrons studded into it

Question 11

What did the gold foil experiment prove?

Answer 11

That atoms have dense nucleuses with a positive charge

Question 12

What is the atomic number of an atom?

Answer 12

The number of protons in an atom

Question 13

What is the mass number of an atom?

Answer 13

The number of protons + the number of neutrons in an atom

Question 14

How do you calculate the number of neutrons in an atom?

Answer 14

Mass number - atomic number

Question 15

How are the electrons arranged in atoms?

Answer 15

Orbiting the nucleus in shells

Question 16

How many electrons can go in the first shell?

Answer 16

2

Question 17

How many electrons can go in the second and third shells?

Answer 17

8

Question 18

What are groups in the periodic table?

Answer 18

The columns, numbered 1, 2, 3, 4, 5, 6, 7, 0

Question 19

What can the group tell you about the electrons in an atom?

Answer 19

How many electrons in the outer shell. E.g. carbon is in group 4 so has 4 electrons in the outer shell

Question 20

What are periods in the periodic table?

Answer 20

The rows in the periodic table

Question 21

What can the period tell you about the electrons in an atom?

Answer 21

How many shells an atom has. E.g. carbon is in the second period so has two shells

Question 22

Why did Mendeleev put some elements in groups?

Answer 22

Because they had similar chemical properties (e.g. they reacted violently with water)

Question 23

What order did Mendeleev put the elements?

Answer 23

In order of atomic weight

Question 24

Why did Mendeleev leave gaps in his periodic table?

Answer 24

For elements that had not been discovered yet

Question 25

What is an ion?

Answer 25

an atom which has lost or gained an electron

Question 26

In terms of electrons, what do group 1 elements have in common?

Answer 26

1 electron in the outer shell

Question 27

In terms of electrons, what do group 7 elements have in common?

Answer 27

7 electrons in the outer shell

Question 28

In terms of electrons, what do group 0 elements have in common?

Answer 28

Full outer shell

Question 29

Explain why the noble gases are inert

Answer 29

They have full outer shells, so do not need to gain or lose electrons

Question 30

What happens to the size of the atoms as you go down a group?

Answer 30

They get bigger by one energy shell

Question 31

What happens to the reactivity of the halogens (group 7 elements) as you go down the group?

Answer 31

They become less reactive

Question 32

What happens to the reactivity of the alkali metals (group 1 elements) down the group

Answer 32

They become more reactive

Question 33

Name LiOH

Answer 33

Lithium hydroxide

Question 34

Name KOH

Answer 34

Potassium hydroxide

Question 35

Explain why the group 1 elements are called alkali metals

Answer 35

They are metals that form alkalis when they react with water

Question 36

What is a displacement reaction?

Answer 36

A reaction in which a more reactive element takes the place of a less reactive element in a compound

Question 37

Explain why the following reaction does not proceed: KBr + I₂

Answer 37

Iodine is less reactive than bromine so cannot displace it

Question 38

Explain why fluorine is more reactive than chlorine

Answer 38

Fewer shells/electrons, less shielding (or stronger attraction from nucleus), easier to gain electrons

Question 39

Explain why potassium is more reactive than lithium (3 marks)

Answer 39

More shells/electrons, less shielding (or weaker attraction from nucleus), easier to lose electrons

Question 40

Explain why bromine is less reactive than chlorine (3 marks)

Answer 40

More shells/electrons, more shielding (or weaker attraction from nucleus), harder to gain electrons

Question 41

Explain why sodium is less reactive than caesium (3 marks)

Answer 41

Fewer shells/electrons, less shielding (or stronger attraction from nucleus), harder to lose electrons