Key Definitions

Atoms of the same element with different numbers of neutrons and different masses

Number of protons and electrons in an atom

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

Particles of an element with different numbers of electrons and protons that also have a charge

The average mass of an atom compared to 1/12 of the carbon 12 atom

The mass of an isotope relative to the mass of 1/12 of the carbon 12 atom

A mole is the amount of a substance that contains as many particles as there are atoms in 12g of carbon

The mass of 1 mole is equal to the relative molecular mass and is written in g/mol

The total number of atoms in 1 mole. There are 6.02x10^23

The actual number of atoms of each element in a compound

The simplest whole number ratio of atoms of each element in a compound

The total atomic masses of each element added together. Relative molecular is used for simple molecules. Relative formula is used for giant structures like ionic

The ratio of an amount in moles in an equation

The amount of substance that is made compared to the theoretical amount of substance.

If a reactant is not in excess, it will be used up first, therefore it is the limiting reagent, this is normally the one with bigger amount of moles.

How well an atom is used up, a perfect atom economy is 100%

When dissolved in water it releases all of its H+ protons and fully dissociates

Only releases a small amount of H+ ions when dissolved in water and partially dissociates.

Metal oxide, metal hydroxide or ammonia Proton acceptor

Base that releases OH- ions when dissolved in water

Product of a neutralisation reaction where its H+ protons are replaced by a metal or ammonium ion.

a region of space where it is most likely to find an electron. It is in an electron cloud that can only hold 2 electrons at a time

the electrostatic attraction between a postive and negative ion to form an ionic compound

the strong electrostatic attraction between a shared pair of electrons and the nucei of the bonded atoms