Flashcards in Topic 6 - Radioactivity Deck (71)
1 What is the difference between an atom and a molecule?
A molecule is two or more atoms bonded together.
2 What is an element?
substance where all atoms have the same atomic number/number of protons
3 What is the part in the middle of an atom called?
4 Name two subatomic particles.
any two from: proton, electron, neutron
5 What are the negatively charged particles in an atom called?
6 What are the positively charged particles in an atom called?
7 Where is most of the mass of an atom concentrated?
8 Which subatomic particles have a negligible mass?
9 How did scientists discover that atoms had tiny nuclei?
fired particles at atoms/gold sheet
10 Who investigated atoms in this way?
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 What charge do electrons have?
negative, or -1
13 How much mass do electrons have?
negligible / hardly any
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 Rutherford investigated the structure of the atom. What did he do?
He fired alpha particles at gold foil.
16 What happened to most of the alpha particles in Rutherford?s experiment?
went straight through
17 Why did Rutherford conclude that most of the mass of the atom was in the centre?
A few particles bounced back.
18 What is the relative mass of a proton?
19 What are isotopes?
atoms of the same element with different masses
20 Which subatomic particle has no charge?
21 What is another name for nucleon number?
22 What is the mass number of an atom?
total number of protons and neutrons
23 What is the atomic number of an atom?
number of protons
24 What is another name for atomic number?
25 What is the relative mass of a neutron?
26 What is the relative charge on a proton?
27 What is different between two isotopes of the same element?
number of neutrons in the atomic nucleus
28 How are electrons arranged in an atom?
29 What is ionisation?
when an atom gains or loses an electron