Unit 1 Flashcards
Atomic number
The number of protons in the nucleus
Mole
The amount of any substance contain as many particles as there are carbon atoms in exactly 12g of carbon-12 isotope.
Mass number
The number of protons and neutrons in the nucleus
Isotope
Atoms of an element with a different number of neutrons.
The relative isotopic mass
The mass of an atom of an isotope compared with 1/12th of the mass of an atom of carbon 12 isotope.
Relative atomic mass
The average mass of an atom of an element compared with 1/12th of the mass of an atom of carbon 12.
Relative molecular mass
The average mass of a molecule compared with 1/12th of the mass of an atom of carbon-12
Relative formula mass
The average mass of a formula of a compound compared with 1/12th of the mass of an atom of carbon-12
1st ionisation energy
The minimum amount of energy required to remove 1 mole of electrons from each atom in one mole of gaseous atoms to form a 1+ ion.
2nd ionisation energy
The minimum amount of energy required to remove one mole of electron from each ion in one mole of gaseous ions to form a 2+ ion.
Atomic orbital
Region within an atom that can hold up to two electrons.
Amount of substance
The quantity whose unit is moles.
Mole
The amount of any substance containing as many particles as there are carbon atoms in exactly 12g of carbon 12 isotope.
Avagadro’s constant
The number of atoms per mole of carbon 12 istope
Molar mass
The mass per mole of a substance.
