Atoms

What do atoms contain?

3 subatomic particles - protons, Neutrons and Electrons

What are protons?

Heavy and positively charged, with a relative mass of 1

What are neutrons?

Heavy and neutral, with a relative mass of 1

What are electrons?

Have hardly any mass (0.0005 - so small that it’s sometimes given as zero) and are negatively charged

What is the nucleus?

It’s in the middle of the atom and contains protons and neutrons. It has a positive charge due to the protons and almost the whole mas of the atom is concentrated in the nucleus. Compared to the overall size of the atom, it’s tiny.

How do electrons move?

In electron shells

Why is an atom neutral?

The charge of the protons (they’re both the same size) is opposite to charge of the electrons so they cancel out

What is an ion?

An atom or group of atoms that has lost or gained electrons

Why is an ion charged?

The number of protons and electrons aren’t equal, meaning it has an overall charge

What does the nuclear symbol on the periodic table represent?

It tells you its atomic (proton) number and mass number

What does the atomic number on the periodic table represent?

It tells you how many protons (and electrons since they’re equal) an atom has - every atom of an element has the same number of protons

What does the mass number on the periodic table represent?

It tells you the total number of protons and neutrons in the atom and its ALWAYS the bigger number

How do you work out the number of neutrons in an atom?

Subtract the atomic number from the mass number