Use Mendeleev’s Periodic Table to predict the formulae for the oxides of the following elements: $\mathrm{K},\mathrm{C},\mathrm{AI},\mathrm{Si},\mathrm{Ba}.$

Metal oxide:

• Metallic oxide is alkaline in nature.
• Almost all metals combine with oxygen to form metal oxides.
• General reaction for the formation of metal oxide: $\mathrm{Metal}+\mathrm{Oxygen}\to \mathrm{Metal}\mathrm{oxide}$

Non-metallic oxide:

• Non-metallic oxides are formed when a non-metal reacts with oxygen gas.
• A non-metallic oxide is acidic in nature.
• General reaction for the formation of non-metallic oxide: $\mathrm{Non}-\mathrm{metal}+\mathrm{Oxygen}\to \mathrm{Non}-\mathrm{metallic}\mathrm{oxide}$

Using the Mendeleev’s Periodic Table, the formula for oxides of the elements is given below:

a) Potassium:

• Potassium $\left(\mathrm{K}\right)$ is a metal and it will form a metallic oxide which is basic in nature.
• The formula for Potassium oxide is ${\mathrm{K}}_2\mathrm{O}$.

b) Carbon:

• Carbon $\left(\mathrm{C}\right)$ is a non-metal and the formula for oxide of carbon i.e. Carbon dioxide is ${\mathrm{CO}}_2$.

c) Aluminium:

• Aluminium $\left(\mathrm{Al}\right)$ is a metal and it can form amphoteric oxide(that behaves as acidic as well as a basic oxide).
• The formula for Aluminium oxide is ${\mathrm{Al}}_2{\mathrm{O}}_3$.

d) Silicon:

• Silicon $\left(\mathrm{Si}\right)$ belongs to Group-$14$ and the formula for its oxide i.e. Silicon dioxide is ${\mathrm{SiO}}_2$.

e) Barium:

• Barium $\left(\mathrm{Ba}\right)$ belongs to Group-$2$ and the formula for its oxide i.e. Barium oxide is $\mathrm{BaO}$.