Topic 6 - Radioactivity Flashcards Preview

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Flashcards in Topic 6 - Radioactivity Deck (71)
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1

1 What is the difference between an atom and a molecule?

A molecule is two or more atoms bonded together.

2

2 What is an element?

substance where all atoms have the same atomic number/number of protons

3

3 What is the part in the middle of an atom called?

nucleus

4

4 Name two subatomic particles.

any two from: proton, electron, neutron

5

5 What are the negatively charged particles in an atom called?

electrons

6

6 What are the positively charged particles in an atom called?

protons

7

7 Where is most of the mass of an atom concentrated?

nucleus

8

8 Which subatomic particles have a negligible mass?

electrons

9

9 How did scientists discover that atoms had tiny nuclei?

fired particles at atoms/gold sheet

10

10 Who investigated atoms in this way?

Rutherford

11

11 Which of the following is approximately the diameter of an atom ? a hundredth of a millimetre, a thousandth of a millimetre or a millionth of a millimetre?

millionth of a millimetre

12

12 What charge do electrons have?

negative, or -1

13

13 How much mass do electrons have?

negligible / hardly any

14

14 In Thompson?s model, the atom was positively charged with tiny negative charges in it. What was this model called?

plum pudding model

15

15 Rutherford investigated the structure of the atom. What did he do?

He fired alpha particles at gold foil.

16

16 What happened to most of the alpha particles in Rutherford?s experiment?

went straight through

17

17 Why did Rutherford conclude that most of the mass of the atom was in the centre?

A few particles bounced back.

18

18 What is the relative mass of a proton?

1

19

19 What are isotopes?

atoms of the same element with different masses

20

20 Which subatomic particle has no charge?

neutron

21

21 What is another name for nucleon number?

mass number

22

22 What is the mass number of an atom?

total number of protons and neutrons

23

23 What is the atomic number of an atom?

number of protons

24

24 What is another name for atomic number?

proton number

25

25 What is the relative mass of a neutron?

1

26

26 What is the relative charge on a proton?

1

27

27 What is different between two isotopes of the same element?

number of neutrons in the atomic nucleus

28

28 How are electrons arranged in an atom?

shells/orbits/energy levels

29

29 What is ionisation?

when an atom gains or loses an electron

30

30 Where are the positive charges in an atom?

nucleus