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Adogadro's Constant The number of atoms or molecules in a moles of a substance is 6.023x10²³.
Atomic Number The number of protons in the nucleus of each atom of an element.
Condensation Reaction Where two reactants react together and eliminate a small molecule (often H2O).
Covalent Bonding Bonding that involves at least one shared pair of electrons between two atoms.
Dative Covalent Bond A covalent bond where both electrons come from only one atom.

Electron shielding

The negative charge of electrons in complete inner shells repel electrons in outer shells and reduce the positive pull of the nucleus.
Electronegativity The ability of an atom to pull electrons towards itself along a covalent bond.
Empirical formula The simplest whole number ratio of the elements present in a compound.
ion A positively or negatively charged atom or a (covalently bonded) group of atoms.
ionic bonding The electrostatic attraction between oppositely charged ions.
ionisation energy The first ionisation energy is the energy required to remove one electron from each atom in a gaseous mole of an element, therefore forming a gaseous mole of ion.
Successive ionisation energies are the sequence of first, second, third, fourth, etc ionisation energies required to remove the first, second, third, fourth, etc electrons from one mole of gaseous atoms of an element.
isotopes Atoms of an element with the same atomic number (protons), but a different atomic mass (neutrons).
isotopic abundance The abundance of each isotope present in a sample of an element.
mass number The total number of protons and neutrons in an atom.
molar mass The mass of one mole of a substance, calculated from its formula.
mole The unit of amount of substance (abbreviated: mol). One mol of a substance is the mass that has the same number of particles (atoms, molecules or electrons) as there are atoms in exactly 12g of Carbon-12.
molecular formula Shows the total number of atoms present in a molecule of a compound.
molecule Covalently bonded group of atoms.
Relative Atomic Mass Ar The average mass of all isotopes of an element, relative to the mass of Carbon-12, which has a mass is exactly 12 g.
Relative Formula Mass The mass of the formula of a compound, relative to the mass of Carbon-12, which has a mass is exactly 12 g.
Relative Isotopic Mass The mass of an isotope of an element, relative to the mass of Carbon-12, which has a mass is exactly 12 g.
Relative Molecular Mass The mass of a molecule of the compound, relative to the mass of Carbon-12, which has a mass is exactly 12 g.
Volatile A low boiling point... readily turns into a gas.
   
   
   
   
   

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