atomic structure

How r elements arranged in a periodic table

By increasing atomic(proton) number

Relationship between position of element in periodic table and electronic configuration

Some group, same number of valence electrons as last digit of group number

Period is number is equal to number of electron shell

What is noble gas configuration?

Unreactive as valence electrons shell is fully filled

Exist on their own as single atoms, monatomic

What are isotopes?

Different atoms of the same element with the same number of protons but different number of neutrons

Why isotopes have the same chemical properties (refers to how element reacts eg do they gain or lose electrons)

They have the same electronic configuration

Why isotopes hav different physical properties ( measurable quantities that do not involve any chemical reactions eg melting boiling points)

Slightly different physical properties as they have different mass number due to different number of neutrons