1.3 Chemical reactions and related calculations

Question	Answer
What happens when elements react?	Their atoms join with other atoms to form compounds
What happens to electrons when elements react?	They are given, taken or shared to form ions or molecules to attain the electron arrangement of the nearest noble gas
What is the relative formula mass of a compound?	The sum of the relative atomic masses of the atoms in the numbers shown in the formula
What is a mole of a substance?	The relative formula mass of a substance, in grams
How can the percentage mass of an element be calculated?	From the relative atomic mass of the element in the formula and the relative formula mass of the compound
How can the empirical formula of a compound be calculated?	From the masses or percentages of the elements in a compound
How can chemical reacions be represented?	By word equations or by symbol equations
How can information about the states of reactants and products be included in chemical reactions?	(g) for gas (l) for liquid (s) for solid (aq) for aqueous solution
Are any atoms lost or made during chemical reactions?	No, so the mass of the products equals the mass of the reactants

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	Created by Anisha Rai about 8 years ago