Physics

Question 1

Most of the mass of an atom is contained within a small dense ____. The nucleus is made of _____ and _____

Answer 1

nucleus
protons
neutrons

Question 2

Protons have a _____ charge and _____ have zero charge. Electrons ____ around the nucleus.

Answer 2

positive
neutrons
orbit

Question 3

Electrons have a negative charge and a small ____

Answer 3

mass

Question 4

The atomic number of an element tells us how many _____ are in the nucleus. The element will also have the same number of ______

Answer 4

protons

electrons

Question 5

The atomic mass of the electrons tells us how many protons and _____ there are in the ______

Answer 5

neutrons

nucleus

Question 6

To calculate the number of neutrons, we subtract the atomic ______ from the atomic _____

Answer 6

number

mass

Question 7

What makes hydrogen unique when compared to other elements?

Answer 7

No neutrons

Question 8

Isotope

Answer 8

Has the same number of protons and electrons but a different number of neutrons

Question 9

What is the atomic structure of a ‘normal’ hydrogen

Answer 9

One proton in nucleus and one electrons orbiting the nucleus

Question 10

What is the difference between an ion and an atom

Answer 10

An ion is a charged atom

Question 11

If an atom gains one electron, what would it’s overall charge be?

Answer 11

-1

Question 12

If an atoms loses one electron, what would it’s overall charge be?

Answer 12

+1

Question 13

Alpha radiation;
1) description
2) electric charge
3 )relative atomic mass
4) penetrating power
5) ionizing effect
6) effect of magnetic/electric field

Answer 13

1) 2 neutrons, 2 protons. An alpha particle is the same s a helium nucleus
2) +2
3) 4
4) stopped by paper or a few cm of air
5) strongly ionizing
6) weakly deflected

Question 14

Beta radiation;

1) description
2) electric charge
3) relative atomic mass
4) penetrating power
5) ionizing effect
6) effect of magnetic/electric field

Answer 14

1) high energy electron
2) -1
3) 1/2000
4) stopped by a few mm of aluminium
5) weakly ionizing
6) strongly deflected

Question 15

Positron (beta plus) radiation;

1) description
2) electric charge
3) relative atomic mass
4) penetrating power

Answer 15

1) high energy and high speed particle/ positive electron/ antimatter
2) +1
3) 1/2000
4) annihilates immediately

Question 16

Gamma radiation;

1) description
2) electric charge
3) relative atomic mass
4) penetrating power
5) ionizing effect
6) effect of magnetic/electric field

Answer 16

1) high energy electromagnetic radiation
2) 0
3) 0
4) stopped by several cm of lead or several m of concrete
5) very weakly ionizing
6) not deflected

Question 17

What happens to cause an atom to emit energy?

Answer 17

an electron moves to a higher orbit (energy level)

Question 18

What happens when an atoms absorbs energy?

Answer 18

An electron moves to a lower orbit

Question 19

What happens when an atom becomes an ion?

Answer 19

The electron completely leaves the orbits

Question 20

The first person to suggest the idea of atoms was the Greek philosopher _______. This idea is a substance is called an element.

Answer 20

Democritus 4500BC

Question 21

The idea that the atomic structure have changed over time. _____ reintroduced the idea that everything is made of atoms. He said atoms were solid of spheres of matter that could not be split.

Answer 21

John Dalton, 1803

Question 22

The discovery of radioactivity. In a radioactive atom, the nucleus is unstable and so it emits particles or waves of radiation to form a more stable atom.

Answer 22

Henri Becquerel, 1896

Question 23

The discovery of tiny particles with a negative charge. Also discovered the existence of electrons. It didn’t fit with Dalton’s model so created a new one. - PLUM PUDDING MODEL

Answer 23

J.J Thomson, 1897

Question 24

Came up with his ‘nuclear’ model of the atom. He made many important discoveries about radioactivity and atomic structure.

Answer 24

Ernest Rutherford, 1911

Question 25

Half life

Answer 25

The time it takes the number of radioactive nuclei in a sample to decrease by 50%

Question 26

Geiger and Marsden’s gold foil experiment

Answer 26

A thin sheet of gold foil was placed in front of a lead box containing alpha radiation.

Question 27

What happened in the gold foil experiment?

Answer 27

1) most alpha particles went straight through the gold foil, without any deflection
2) some alpha particles were slightly deflected by the gold foil
3) a few alpha particles were bounced back from the gold foil

Question 28

What were the results of the gold foil experiment?

Answer 28

• Most of the atom is empty space
• It has positive charge and most of its mass is in a tiny central nucleus
• Electrons orbit the nucleus at a distance, like planets around the sun

Question 29

What does fluorescent mean? Explain what happens to make a fluorescent material appear really bright?

Answer 29

A fluorescent material absorbs some electromagnetic energy and then emits it straight away. The emitted energy usually has a longer wavelength than the absorbed energy; UV is absorbed and re-emitted as visible light.

Question 30

Explain the difference between a ‘fluorescent’ material and a ‘phosphorescent’ material.

Answer 30

A phosphorescent material emits the electromagnetic energy it has absorbed much later after doing so however fluorescent materials emits the energy straight away

Question 31

Background radiation

Answer 31

Natural sources of radiation (and artificial sources)

Question 32

Why are plants radioactive?

Answer 32

They take in carbon-14 from the atmosphere

Question 33

Why do we increase our own radiation levels by eating meat?

Answer 33

The cows eat the radioactive grass with the carbon-14 in it as well as breathing it in on a daily basis. This will keep happening until they die which is when they are used to sell, cook and eat their meat.

Question 34

Why is a wooden table or shelf radioactive?

Answer 34

The wood was once a living tree breathing in the carbon-14 during photosynthesis

Question 35

2 examples of medical sources of background radiation?

Answer 35

X-rays and CT scanner

Question 36

What are cosmic rays? What objects in space do they come from?

Answer 36

A highly energetic atomic nucleus or other particle travelling through space at a speed approaching that of light

Question 37

What is radon gas? Where does it come from? Why is it dangerous to humans?

Answer 37

Radon is a naturally-occurring radioactive gas that can cause lung cancer. Radon gas is inert, colourless and odourless. Radon is natural in the atmosphere in trace amounts

Question 38

Why do we need to measure the background radiation count in a room before carrying out an experiment?

Answer 38

To get a more accurate reading that is not impacted by any radiation sources that could be present due to the experiment

Question 39

Which source of background radiation contributes the most to the overall total?

Answer 39

Radon gas

Question 40

Which source of background radiation contributes the least to the overall total?

Answer 40

nuclear power and weapons

Question 41

What is the percentage of background radiation that comes from rocks and buildings?

Answer 41

14%

Question 42

Which form of background radiation is largely caused by absorption of the radioisotope carbon 14?

Answer 42

rocks and buildings

Question 43

Which type of background radiation would increase if you were in an aero-plane?

Answer 43

Cosmic rays

Question 44

Why might accident prone people end up being exposed to more radiation than other people?

Answer 44

Because if they need an X-ray they will absorb the radiation from the x-ray