STARTER
Copy and complete;
We added Sodium Hydroxide, which is
an a______ drop by drop to
hydrochloric acid, which is an a_____.
We n__________ the solution which
formed Sodium Chloride and water.
Sodium Chloride is more commonly
known as table s______ .
Compounds
LO
1. Know how to name compounds
2. Know how to write formulas
3. Know how to work out how many
of each atom there are in a
compound, based on a formula
Formation of compounds
Compounds are substances formed from two or more
elements , the atoms of each are in fixed proportions
and they are held together by chemical bonds.
Only electrons are involved in making bonds, nuclei are
not affected at all while making bonds. A chemical
reaction is needed to make a compound from
elements and it is usually difficult to separate the
original elements of a compound out again. A chemical
reaction is needed to do this.
The properties of compounds are totally different from
the properties of the original elements.
Formation of compounds
Compounds with ionic bonding
A compound which is made from a metal and a non
metal consists of ionic bonds.
Metal atoms lose electrons to form positive ions.
Non metal atoms gain electrons to form negative ions.
Opposite charges of the ion attract each other strongly, this
is called ionic bonding.(e.g. sodium chloride, magnesium
oxide)
An ion is a charged particle formed when an atom, or a
group of atoms, loses or gains electrons.
Compounds with covalent bonding
Compounds formed from non metals have
covalent bonding. Atoms of non metals share
electrons to make bonds called covalent
bonding.(e.g. Hydrogen chloride,water)
Formulas and Equations
Symbol represent elements, Formula represent
compounds. Word equations and balanced
chemical equations show the changes that
happen in chemical reactions.
A formula shows the number of atoms of each
element in a unit of the compound.
NH3
How many
elements? Atoms?
H2SO4
How many elements?
Atoms?