The nuclear atom - nuclear model of the atom

Question 1

What are subatomic particles?

Answer 1

The protons, neutrons and electrons that make up an atom

Question 2

What are nucleons?

Answer 2

Protons and neutrons - make up the nucleus

Question 3

What are the relative masses and charges of subatomic particles?

Answer 3

Proton, neutron, electron, respectively:
Relative charge: +1, 0, -1
Relative mass: 1, 1, negligible

Question 4

What are the key factors of the nucleus?

Answer 4

1. very small in comparison to the atom itself
2. highly dense structure, the mass of an atomm is concentrated in the nucleus
3. has a positive charge

Question 5

Describe the structure of an atom

Answer 5

• positively charged nucleus composed of nucleons
• negatively charged electrons orbit the nucleus
• electrostatic attraction between positive nucleus & negatively charged electrons hold atom together

Question 6

What is the atomic number?

Answer 6

The number of protons in the nucleus of an atom.
Has the symbol Z
= the number of electrons in a neutral atom

Question 7

What is the mass number?

Answer 7

The number of protons & neutrons (nucleons) in the nucleus of an atom.
Has the symbol A

Question 8

How can the number of neutrons be calculated?

Answer 8

Number of neutrons = mass number - atomic number

Question 9

What is the difference in electrons and protons between positively and negatively charged ions?

Answer 9

A positively charged ion has lost electrons and therefore has fewer electrons than protons.
A negatively charged ion has gained electrons and therefore has more electrons than protons.