C2 Atoms, Ions, Isotopes

Question 1

What do atomic number and mass number describe?

Answer 1

They tell you how many of each kind of subatomic particle an atom has

Question 2

Which number is the bigger number for atomic and mass numbers?

Answer 2

Mass

Sometimes it is writing the opposite way round, just remember the bigger number is the mass

Question 3

What does the atomic number tell us?

Answer 3

How many protons there are.

Sometimes called proton number

Question 4

Complete the sentence

Atoms of the same element all have the same number of…..

Answer 4

Protons

Question 5

Complete the sentence

Atoms of different elements have ……… numbers of protons

Answer 5

Different

Question 6

How do you work out the number of neutrons?

Answer 6

Subtract the atomic number from the mass number.

Question 7

Which number is always bigger?

Answer 7

The mass (nucleon) number

Question 8

Why do neutral atoms have no charge overall?

Answer 8

Because they have the same number of protons as electrons.

The charge on the electrons is the same size as the charge on the protons, but opposite - so the charges cancel out.

Question 9

Complete this sentence

The number of electrons in a neutral atom is equal to ………..

Answer 9

…..the atomic number.

Question 10

When do ions form?

Answer 10

Ions form when atoms (or groups of atoms) gain or lose electrons.

Question 11

When do negative ions form?

Answer 11

When atoms gain electrons.

They have more electrons than protons.

Question 12

When do positive ions form?

Answer 12

When atoms lose electrons.

They have more protons than electrons.

Question 13

Ions

F-

Answer 13

There’s a single negative charge, so there must be one more electron than protons.

Question 14

F has an atomic number of 9, so how many electrons are there in F-?

Answer 14

10 electrons

9+1=10

Question 15

ions

Fe2+

Answer 15

There’s a 2+ charge, so there must be two more protons than electrons.

Question 16

Fe has an atomic number of 26, how many electrons are there in Fe2+?

Answer 16

24 electrons

26-2=24

Question 17

What are isotopes?

Answer 17

Different forms of the same element, which have the same number of protons but a different number of neutrons.

Question 18

What are the atomic and mass numbers of isotopes?

Answer 18

Same atomic number but different mass numbers.

Question 19

Why do isotopes have the same atomic number?

Answer 19

If they had different atomic numbers, they’d be different elements altogether.

Question 20

An example of the two main isotopes of carbon

Answer 20

Carbon -12
12 C
6 C
6 protons
6 electrons
6 neutrons

Carbon-13
13 C
6 C
6 protons
6 electrons
7 neutrons

Question 21

Read p 18 for info about isotopes

Answer 21

.

Question 22

Bromine has an atomic number of 35. It exists naturally with 2 isotopes, bromine-79 and bromin-81. Work out how many neutrons, protons and electrons are in each isotopes. (2 marks)

Answer 22

Bromine -79: 35 protons,35 electrons and 44 neutrons
(79-35=44) (1 mark)

Bromine-81: 35 protons, 35 electrons and 46 neutrons
(81-35=46) (1 mark)

Question 23

Bromine has n atomic number of 35.

Bromine tends to react by forming Br- ion. How any electrons are in a Br- ion?(1 mark)

Answer 23

35 + 1 =36 electrons