C3 Flashcards
What is the law of conservation of mass?
No atoms are lost or made during a chemical reaction, so the mass of product equals the mass of reactants
What is the key rule in an ionic compound?
the charges of the ion have to cancel out to equal zero
What is relative formula mass (Mr)?
sum of the relative atomic masses of each atom within the molecule
How do you calculate the percentage of mass of an element?
Percentage by Mass of an element =total relative atomic mass of the atoms of the element / relative formula mass of compounds x 100
How big is one mole?
6.02x10^23
What is the equation for the number of moles in an element ?
Number of moles = mass (G)/ relative atomic mass (Ar)
What is Avagadros constant?
one mole
What is the equation for the number of moles in an compound ?
Number of moles = mass (G)/ relative formula mass (Ar)
what is relative atomic mass
average mass of atoms in an element taking into account masses and abundance of isotopes
what is a limiting reactant
the reactant that is completely used up
why are some metals more reactive then other
-contain more energy levels
-outer electron is further from nucleus
-weaker attraction between nucleus and outer electron
-outer electron is more easily lost
why did the early periodic table misplace elements
-early periodic tables were arranged with elements in order of their atomic weights
-placed elements with same similar properties together
how do you convert cm into dm
divide by 1000
how to predict products of simple displacement reaction
A+BC->B+AC
