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Electronegativity: Trends Electronegativity varies across Periods and down the Groups of the Periodic Table Down a group There is a decrease in electronegativity going down the Group The nuclear ch...
Electronegativity: Definition Electronegativity is the ability of an atom to attract a pair of electrons towards itself in a covalent bond This phenomenon arises from the positive nucleus’s ability...
Mole Calculations The number of moles of a substance can be found by using the following equation: It is important to be clear about the type of particle you are referring to when dealing with mole...
Water of Crystallisation Water of crystallisation is when some compounds can form crystals which have water as part of their structure A compound that contains water of crystallisation is called a ...
Empirical & Molecular Formulae The molecular formula is the formula that shows the number and type of each atom in a molecule Eg. the molecular formula of ethanoic acid is C2H4O2 The empirical ...
Balancing Equations A symbol equation is a shorthand way of describing a chemical reaction using chemical symbols to show the number and type of each atom in the reactants and products A word equat...
Formulae of Ionic Compounds Ionic compounds are formed from a metal and a nonmetal bonded together Ionic compounds are electrically neutral; the positive charges equal the negative charges Charges ...
Mole & Avogadro Constant The Avogadro constant (NA or L) is the number of particles equivalent to the relative atomic mass or molecular mass of a substance The Avogadro constant applies to atom...
Relative Masses Atomic Mass Unit The mass of a single atom is so small that it is impossible to weigh it directly Atomic masses are therefore defined in terms of a standard atom which is called the...
