Elements, Compounds and Mixtures
1. Write below each of the following if it is an element, compound or mixture.
O2
CO2
H2
HF
Fe
Sodium
chloride
iron
Potassium
oxide
sand
gold
H2S
C60
Lithium helium
flouride
MgO
A dog
2. Look at the diagrams below and decide whether each one represents the
particles in an element, compound or mixture. Different colour atoms represent
atoms of different elements.
i.
ii.
iii.
iv.
v.
vi.
3. Look at the compounds in the table below. For each one, write the elements
which make up each compound and how many atoms of each element there are. The
first has been done for you.
Chemical
formula
MgBr2
KI
CuCl2
K2O
Fe2O3
CaCO3
Al2(SO4)3
Elements and atoms
the compound is made of
Magnesium (1 atom), bromide (2 atoms)
4. Do you notice anything about the first and last elements in each of the first
four compounds? Don’t worry about the last two compounds, they are a special
case.
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