4.4.1.1 - The structure of an atom

What is the radius of an atom?

Roughly 1 × 10 to the power of -10

(0.1nm)

How much smaller is the radius of a nucleus to the radius of the atom?

The radius of a nucleus is less than 1 / 10000 of the radius of an atom

So 1 × 10 to the power of -14 metres

Where is most of the atom’s mass concentrated?

In it’s positively charged nucleus

What sub atomic particles does the nucleus contain?

Protons and Neutrons

What is the overall charge of an atom?

The overall charge of the atom is neutral

Why is the overall charge of the atom neutral?

As the number of protons in an atom equal the number of electrons in an atom

How are electrons arranged in an atom?

Electrons are arranged in different distances form the nucleus

So electrons orbit the nucleus at different energy levels / shells

What can cause the electron arrangement to change?

The electron arrangement can change with the absorption or emission of electromagnetic radiation

Absorb em radiation = move further from the nucleus to a higher energy level

Emit em radiation = move closer to the nucleus to a lower energy level