The document discusses the steps for writing and balancing chemical equations. It explains that reactants are identified and written on one side of the equation, and products are written on the other side. Chemical symbols are used to write unbalanced equations, and the numbers of atoms are adjusted to balance the equation so there are the same number of each type of atom on both sides. Signs that a reaction occurred include the release or absorption of energy as heat or light.

2. +Berylium cation with a charge
of 2 is bonded with fluoride
anion with a charge of 1.

3. +Aluminium cation with a
charge of three is bonded to
sulfide anion with a charge of
2.

4. + Step 1 – Identify the reactants and the
products.
+ Think about making a cake. The ingredients
are the reactants and the cake is the product

5. + Step 2 – Write a word equation.
+ Reactants are on one side and products on the
other.
+ Reactant + Reactant  Product + Product

6. + Step 3 – Write an unbalanced chemical
equation.
+ Replace the names of each substance with
their chemical names. (chemical symbols)

7. + Step 4 – Balance the equation.
+ When there is an uneven number of atoms on
each side of the equation.
+ You cannot change the make up of the
substances only increase the amount of the
whole substance.

8. +H2 + O2  H2O
+H2 + Cl2  HCl
+H2 + N2  NH3

9. +What are the signs that a
chemical reaction has taken
place.

10. + Energy takes the form of heat or light.
+ When energy is released during a chemical
reaction it is know as an exothermic reaction.
+ When a reaction takes in energy it is known as
an endothermic reaction.

11. + Absorbs energy from their surroundings,
cooling them down.
+ If the reaction took place in a solution of
water you would be able to measure a
decrease in temperature.

12. + Release energy as heat or light.
+ Combustion
+ Corrosion
+ Respiration

13. +2Ca +O2  CaO
+C3H8 + 4H2O + CO2
+2Li + H2O  LiOH + H2