1.1 - 2-9 Flashcards
What is an ion?
A positively or negatively charged atom or group of atoms.
What are isotopes?
Atoms of the same element with different numbers of neutrons.
What is relative isotopic mass?
The mass of an atom of an isotope compared with one twelfth of the mass of an atom of carbon-12.
What is relative atomic mass?
The weighted mean mass of an atom of an element compared with one twelfth of the mass of an atom of carbon-12.
What is relative molecular mass?
The weighted mean mass of a molecule compared with one twelfth of the mass of an atom of carbon-12.
What is relative formula mass?
The weighted mean mass of a formula unit compared with one twelfth of the mass of an atom of carbon-12.
Amount of substance
The quantity whose unit is the mole.
Avogadro Constant.
Number of atoms per mole of the carbon-12 isotope (6.02 x 10^23 mol^-1).
What is a mole?
The amount of any substance containing as many particles as there are carbon atoms in exactly 12g of the carbon-12 isotope.
Molar mass
The mass per mole of a substance (g mol^-1).
Equation for the mole
n = m/M
n = amount of substance (mol) m = mass (g) M = molar mass (g mol^-1)
Empirical formula.
The simplest whole number ratio of atoms of each element present in a compound.
Molecular formula
The actual number of atoms of each element in a compound.
Molar volume
The volume per mole of a gas (dm^3 mol^-1). At room temperature and pressure, the molar volume is approximately 24.0 dm^3 mol^-1.
Equation for gas volumes in dm^3
n = V/24
