Atomic Theory & Radioactivity

Question 0

What is an element?

Answer 0

A substance mad from one or more types of atoms

Question 1

What is an atom?

Answer 1

Smallest particle of matter

Question 2

What is a compound?

Answer 2

A substance made from two or more different types of atoms

Question 3

What is a molecule?

Answer 3

A substance made from two or more atoms that are chemically combined. It doesn’t matter if they are the same or different types of atoms but they must all be non-metals.

Question 4

What is a lattice?

Answer 4

A substance made from two or more atoms that are chemically combined. It doesn’t matter if they are the same or different atoms. Usually they include a metal, except for diamond and graphite.

Question 5

What is a mixture?

Answer 5

Contains two or more different substances that are not chemically combined. It may be a combination of atoms/molecules/elements/compounds.

Question 6

What is a pure substance?

Answer 6

Only one type of substance

Question 7

What are nucleons?

Answer 7

Protons and neutrons

Question 8

What are protons?

Answer 8

Protons have a positive charge and they are located in the nucleus of an atom.

Question 9

What are neutrons?

Answer 9

Have no charge and are located in the nucleus of an atom.

Question 10

What are electrons?

Answer 10

They have a negative charge and are located in the outer shells of an electron. The are much lighter than protons and neutrons.

Question 11

What does the atomic number of an atom represent?

Answer 11

The number of protons (and therefore electrons) in an atom

Question 12

What does the atomic mass number represent?

Answer 12

The number of protons plus the number of neutrons

Question 13

What is an isotope?

Answer 13

Isotopes have the same atomic number but a different mass number indicating a different number of neutrons.

Question 14

What are ions?

Answer 14

Ions are charged atoms and are made when an atom either accepts or gives away electrons.

Question 15

What is an anion?

Answer 15

A negatively charged ion

Question 16

What is a cation?

Answer 16

A positively charged ion

Question 17

What is the relationship between location in the periodic table and the number of electrons in the outermost shell?

Answer 17

The amount of electrons in the outermost shell corresponds with the group number.

Question 18

What is the relationship between location in the periodic table and the number of electron shells?

Answer 18

The period in which the atom is located on the periodic table is the same as the amount of shells an atom has.

Question 19

What are valence electrons?

Answer 19

Electrons in the outermost shell

Question 20

What are the noble gases?

Answer 20

They are located on the far right side of the periodic table and have a low reactivity due to their valence shell being full.

Question 21

What is radioactivity?

Answer 21

Is when atoms emits radioactive particles or rays in order to maintain stability in the the nucleus

Question 22

What causes radiation?

Answer 22

When the nucleus of an atom becomes unstable

Question 23

How does radiation happen?

Answer 23

When the nucleus is unstable it tries to become stable by losing a small ‘bit’ of
itself. This means that is changes into a different element (called a daughter isotope) and an extra ‘bit’

Question 24

What are the three types of radiation?

Answer 24

Alpha, beta and gamma

Question 25

What happens in alpha radiation?

Answer 25

An alpha particle has two protons and two neutrons, giving it a positive charge. When an atom emits alpha radiation, the atoms mass number decreases by 4 and the atomic number decreases by 2. As a result of the loss of two protons the atom becomes a different element

Question 26

What happens in beta radiation?

Answer 26

A beta particle is the same as an electron except that it is created in the nucleus. Beta emission occurs in elements with more neutrons than protons, so a neutron splits into a proton and an electron. The proton stays and the electron is emitted.

Question 27

What is gamma radiation?

Answer 27

When a nucleus is in an excited state (usually after it has emitted alpha or beta particles) it may emit one or more photons. Gamma rays do not change the atomic number or mass of the atom but rather move it from a higher energy state to a lower energy state.

Question 28

What are the two methods of measuring radiation?

Answer 28

Becquerels and half-life

Question 29

What is the becquerel?

Answer 29

It is a measure of how many atoms break down per second. 1bq is the same as one emission per second.

Question 30

What is a half-life?

Answer 30

The time it takes for half of a radioactive material sample to decay or break down.

Question 31

What is a use for alpha radiation?

Answer 31

Alpha radiation is used in smoke alarms to detect smoke. The alpha radiation ionises the air particles inside the smoke dectector. This allows a small electric current to flow. Smoke causes the amount of ionised air particles to drop, setting off the alarm.

Question 32

What is a use for beta radiation?

Answer 32

Doctors may use radioactive chemicals called tracers for medical imaging. Certain chemicals concentrate in different, damaged or diseased parts of the body. Radiation detectors create a picture of this.

Question 33

What is a use for gamma radiation?

Answer 33

Gamma radiation is used in the treatment of cancer to kill the cancer cells.

Question 34

Which is the most damaging form of radiation inside the body?

Answer 34

Alpha is the most dangerous type of radiation to have in your body as it releases lots of energy in a small space.

Question 35

What is the most dangerous form of radiation externally?

Answer 35

Gamma radiation because it can penetrate the body.