Topic 6 - Radioactivity - The Nucleus

Question 1

Give an approximation for the radius of an atom

Answer 1

1 x 10⁻¹⁰ metres

Question 2

What are the three subatomic constituents of an atom

Answer 2

1) proton
2) neutron
3) electron

Question 3

Where is the most of the mass of an atom is concentrated

Answer 3

In the nucleus

Question 4

Approximately what proportion of the total radius of an atom is the radius of the nucleus

Answer 4

1/10,000

Question 5

Describe the arrangement of protons, neutrons and electrons in an atom

Answer 5

Protons and neutrons are found in the atoms nucleus

Electrons are found in discrete energy levels around the nucleus

Question 6

What type of charge does the nucleus of an atom have and why

Answer 6

It has a positive charge

The nucleus contains protons and neutrons

Protons have a positive charge and neutrons have no charge

Question 7

Give two ways that an atoms electron arrangement can be changed

Answer 7

1) Absorbing electromagnetic radiation

2) emitting electromagnetic radiation

Question 8

Explain how an atoms electron arrangement changes when it absorbs EM radiation

Answer 8

Electrons move to higher energy levels

And they can move far away from the nucleus

Question 9

Explain how an atoms electron arrangement changes when it emits EM radiation

Answer 9

Electrons move to a lower energy level

They move towards the nucleus

Question 10

How does the ratio of electrons to protons in an atom result in the atom having no overall charge

Answer 10

The number of protons is equal to the number of protons

Protons and electrons have equal and opposite charges so charges cancels

Question 11

What do all forms of the same element have in common

Answer 11

The number of protons is equal

Question 12

What is the name given to the number of protons in an atom

Answer 12

Atomic number

Question 13

What is an atoms mass number

Answer 13

The total number of protons and neutrons in the atom

Question 14

What is an isotope of an atom

Answer 14

An atom of an element that has a different number of neutrons but the same number of protons

Question 15

What property differs between isotopes of an atom

Answer 15

The mass number of the atom

Question 16

How do atoms turn into positive ions

Answer 16

1) They lose one or more of their outer electrons

2) electrons are negatively charged, so it the resultant charge of the atom is positive

Question 17

What are the relative masses of a proton, neutrons and electrons and electron

Answer 17

1 - proton
1 - neutron
1/1850 - electron

Question 18

What is the relieve charge of a proton

Answer 18

+ 1

Question 19

What is the relative charge of an electron

Answer 19

• 1

Question 20

What is the top number of an element

Answer 20

The mass number

Question 21

What is the mass number made of

Answer 21

Protons + neutrons

Question 22

What is the bottom number of an element called

Answer 22

Atomic number

Question 23

What is the atomic number made of

Answer 23

Just protons