1What is atomic no. ?
the number of protons and electrons
2What is atomic mass?
the number of protons and neutrons
3What is relative formula mass?
the sum of the relative atomic masses of all atoms in a formula
4How do you find percentage by mass?
individual mass / total mass x 100
5What is the law of conservation of mass?
Atoms can’t be created or destroyed; the mass of the reactants must equal the mass of the products
6What does accuracy mean?
how close you get to an answer
7What does precision mean?
how close a set of results or measurements are
8What is resolution?
the smallest measurable part of a unit
9What is 1 mole (Avogrado’s Constant)?
6.022 x 10*23 particles
10What will 1 mole of a certain atom weigh?
The element’s relative atomic mass
11How many grams of oxygen would equal 1 mole?
16g
12How do you work out the moles from an amount of a certain element?
mass / relative formula mass
13What are excess reactants?
where there’s more reactant than necessary
14What are limiting reactants?
where the amount of reactant affects how much product is made; will be used up first and stops the reaction