Atoms (Kind of the whole topic)

Question 1

What is the symbol for relative atomic mass?

Answer 1

Ar

Question 2

The Σ means

Answer 2

The sum of

Question 3

Electron configuration tells us what?

Answer 3

Electron configuration tells us how an atom’s electrons are organised.
The inner shell (closest to the nucleus) can have a maximum of 2 electrons and the next two shells can have a maximum of 8 electrons.
Any extra electrons are then put into a fourth shell.

Question 4

The further/closer a shell is to the electrons/nucleus, the lower its energy level, so the first shell that is filled is the closest to the nucleus.

Answer 4

The closer a shell is to the nucleus, the lower its energy level, so the first shell that is filled is the closest to the nucleus.