Which are subatomic particles

What is important to study for nios grade 12 chemistry? i have only one month left.

The formation of a solid, also known as a is an indication of a chemical change. precipitate particulate particle powder

Draw any one of the skeletal structures of a 2° alkyl bromide having the molecular formula of c6h13br and two stereogenic centers. indicate chirality by using wedge and hashed wedge notation. lone pairs do not need to be shown.