Chemistry - Unit 2: Atoms, elements and compounds

what is an element?

a substance made up of only one type of atom

what is a compound?

a substance made from 2 or more elements that have reacted with each other and formed chemical bonds between atoms.

what is a mixture?

a substance made up of 2 or more elements or compounds, but aren’t chemically bonded together

describe the structure of an atom.

a central nucleus containing neutrons and protons surrounded by electrons in shells

what is the relative charge of protons?

+1

what is the relative charge of neutrons?

0

what is the relative charge of electrons?

-1

what is the relative mass of protons?

1

what is the relative mass of neutrons?

1

what is the relative mass of electrons?

1/1840

what is atomic/proton number?

the number of protons in the nucleus of an atom

what is mass/nucleon number?

the total number of protons and neutrons in the nucleus of an atom