Topic 1 Atoms

Question 1

What is the radius of an atom?

Answer 1

0.1nm (1x10^-10m)

Question 2

Facts about the nucleus

Answer 2

In the middle of the atom
Contains protons and neutrons
Radius of 1*10^-14
Has a positive charge because of its protons
Almost the whole mass is concentrated there

Question 3

Facts about electrons

Answer 3

Move around nucleus in electron shells
Negatively charged and tiny but cover a lot of space
Volume of orbits determines size of atom
Virtually no mass

Question 4

Relative mass and charge

Answer 4

Particle Relative mass. Charge
Proton. 1. +1
Neutron. 1. 0
Electron Very small. -1

Question 5

Why are atoms neutral and have no charge?

Answer 5

Because they have the same number of protons and neutrons which cancel each others charge out

Question 6

Why do ions have charge?

Answer 6

Because the number if protons don’t equal the number of electrons
E.g ion with 2- charge has 2 more electrons

Question 7

Atomic number

Answer 7

How many protons

Question 8

Atomic mass number

Answer 8

How many protons and neutrons