Which of the following are decomposition reactions? CH4 (g) + O2 (g) → CO2 (g) + H2O (l) CaO (s) + CO2 (g) → CaCO3 (s) Mg (s) + O2 (g) → MgO (s) PbCO3 (s) → PbO (s) + CO2 (g)

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)