Unit 1 Definitions Flashcards
Define: Isotope
Atoms of the same element, with a different number of neutrons
Define: Ion
+ve or -ve charged atom or group of atoms
Define: Relative isotopic mass
The mass of an isotope of an atom compared to 1/12 of the mass of an atom of carbon-12
Define: Relative atomic mass
And similarly, relative molecular mass and relative formula mass.
The weighted mean mass of an atom (molecule/formula unit) compared with1/12 of the mass of an atom of carbon-12
Define: Avogadro’s constant
The number of atoms per mole of the carbon-12 isotope (6.02x10^23 mol^-1)
Define: A mole
The amount of a substance containing as many particles as there are carbon atoms in 12g of carbon-12
Define: Amount of a substance
Is the quantity whose unit is the mole.
Define: Molar mass
The mass per mole of a substance
Define: Empirical formula
The simplest whole number ratio of atoms of each element in a compound.
Define: Molecular formula
The actual number of atoms of each element in a molecule
Define: Acid
An acid is a proton donar. E.g. HCl, sulfuric acid (H2SO4) and nitric acid (HNO3)
Define: Base
Big dirty stinking proton receiver. E.g. metal oxides, metal hydroxides, ammonia
Define: Alkali
A base which dissolves in water to release OH- ions in an aqueous solution
Define: Salt
When the H+ ion of an acid is replaced by a metal ion or NH4+
Define: First ionisation energy
The energy required to remove an electron each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions
