Particles and Radiation Flashcards Preview

A Level Physics Year 1 > Particles and Radiation > Flashcards

Flashcards in Particles and Radiation Deck (181)
Loading flashcards...
1

What is a nucleon?

A particle in the nucleus (protons and neutrons)

2

What is the relative mass of an electron?

1/1840

3

What is the proton number?

Number of protons in the nucleus

4

What defines what an element is?

The number of protons

5

What do an element's reactions and chemical behaviour depend on?

Number and arrangement of electrons

6

What is the mass number?

Number of protons and neutrons in the nucleus

7

In physics, what does 'specific' mean?

Per unit mass

8

What is the specific charge of a particle?

The ratio of its charge to its mass

9

What is the SI units of specific charge?

C kg^-1

10

What is the equation for specific charge?

Specific charge = Charge / Mass

11

What is a fundamental particle?

A particle that cannot be split up into anything smaller, such an electron

12

What is an isotope?

An atom of an element with the same number of protons, but a different number of neutrons

13

What does changing the number of neutrons of an atom affect?

The stability of the nucleus

14

In general, the greater the number of neutrons compared with the number of protons...?

The more unstable the nucleus is

15

What do unstable nuclei do?

Decay to make themselves more stable

16

What isotopic data?

The relative amounts of isotopes in a substance

17

What is the electromagnetic force?

A fundamental force that causes interactions between charged particles

18

What does the electromagnetic force cause in the nucleus?

The positively charged protons to repel each other

19

What does the gravitational force in the nucleus cause?

All the nucleons in the nucleus to attract each other due to their mass

20

Which is a bigger force in the nucleus, the repulsion from the electromagnetic force or attraction from the gravitational force?

The repulsion from the electromagnetic force

21

What is the strong nuclear force?

A fundamental force with a short range which is attractive at short separations, but repulsive at very small separations

22

What is the strong nuclear force responsible for?

The stability of the atom

23

What are interactions that use the strong nuclear force called?

Strong interactions

24

What separation of nucleons is the strong nuclear force repulsive for?

Less than 0.5 fm (5x10^-16 m)

25

Describe the strong nuclear force once the nucleon separation has increased past 0.5 fm?

The strong nuclear force becomes attractive, reaching a maximum attractive value, the falling rapidly to zero after about 3 fm (3x10^-15)

26

What is nuclear decay?

When unstable nuclei will emit particles to become more stable

27

What is an alpha particle?

The nucleus of a helium atom

28

Alpha decay can only happen in...?

Very large atoms with more than 82 protons

29

Why are very large atoms, such as uranium, very unstable?

Because they're so big that the strong nuclear charge can't keep them stable

30

How do very large atoms become more stable?

They release an alpha particle from their nucleus