1ai: Atomic Structure - YK

Question 1

What is the structure of an atom?

Answer 1

Protons and neutrons together in a dense nucleus ‘orbited’ by electrons in energy levels (shells)

Question 2

What are the relative charges of the main subatomic particles?

Answer 2

Proton: +1; Neutron: 0 (neutral / no charge); Electron: -1

Question 3

What are the relative masses of the main subatomic particles?

Answer 3

Proton: 1; Neutron: 1; Electron: 1/1836 (about 1/2000, negligible)

Question 4

How is the modern periodic table ordered?

Answer 4

By number of protons in the nucleus

Question 5

What is the mass number of an atom?

Answer 5

Sum of the number of protons and neutrons in an atom’s nucleus, also called nucleon number

Question 6

What is the atomic number?

Answer 6

The number of protons in an atom’s nucleus, same as proton number

Question 7

What are isotopes?

Answer 7

Isotopes are atoms of the same element with different numbers of neutrons

Question 8

What is relative atomic mass?

Answer 8

Weighted average of the mass numbers of all isotopes of an element relative to carbon 12