P6

Question 1

The _____ in the nucleus, or number of _____, tells you which element it is. In a neutral atom, this is also equal to the number of _____.

Answer 1

charge, protons, electrons

Question 2

All three types of radiation are _____ radiation

Answer 2

ionising

Question 3

Radioactive decay is random. Explain what that means.

Answer 3

Random means that an event is equally likely in any time interval.

Question 4

The emission spectrum of helium contains bright lines at certain frequencies.
Explain how the lines are produced.

Answer 4

Electrons from higher levels fall down to a lower energy levels and emit a photon of light.
Different transitions produce photons of different energy,
and so of a different frequency.

Question 5

Describe what can happen when an atom absorbs electromagnetic radiation?

Answer 5

An electron moves up from one energy level to another.

Question 6

Describe and explain the difference between the electromagnetic radiation emitted from atoms and the electromagnetic radiation emitted from nuclei.

Answer 6

The energy of the electromagnetic radiation emitted by nuclei is higher than that of the energy of the electromagnetic radiation emitted by atoms because the energy of levels in nuclei are higher.

Question 7

What is an isotope?

Answer 7

Atoms with the same atomic number but different mass number.
It has same protons and electrons but different neutrons.

Question 8

How does the geiger counter work?

Answer 8

counter is used to measure the amount of radiation.

the clicks heard are tiny currents produced when the radiation ionises atoms of the gas inside the tube.

Question 9

What happens during alpha decay?

Answer 9

the atomic number of the new nucleus decrease by 2 and the mass number decreases by 4
240 Pu –> 236 U + 4 He
94 92 2

Question 10

Compare nuclear fusion and fission

Answer 10

Fission and Fusion are nuclear reactions that produce energy but the applications are not the same. Fission is the splitting of a heavy unstable nucleus into two lighter nuclei. Fusion is the process where the two lighter nuclei can join to create a large nucleus. This produces a lot of energy.

Question 11

Explain electron energy levels

Answer 11

Electrons sit in different electron shells.
Inner shells can move up a shell if it absorbs electromagnetic radiation and energy. It will move to a. partially filled or empty shell and get excited.
It will move back down and lose same amount of energy absorbed. and electromagnetic radiation moves out.

Question 12

In the electromagnetic spectrum which has the highest frequency and shortest wavelength

Answer 12

Gamma ray

Question 13

How is an atom ionised

Answer 13

If outer electron absorbs radiation it can leave atom .

Atom is a positive ion because more protons than electrons. The more electrons lost the greater the + charge

Question 14

How do fluorescent tubes work in terms of electrons

Answer 14

They are made up of mercury vapour, it gets excited , returns to original , emits ultraviolet.
The phosphor inside the tube absorbs ultraviolet and excites again.
Moves back down, emitting different frequencies - ALL visible part of spectrum

Question 15

What is the loss in beta

Answer 15

0
-1
electron with no mass

Question 16

What is the loss in gamma

Answer 16

0
0
it is energy it does not change element.