Classify the following molecules as polar or non$-$polar. Explain why in each case. $($value $6)$

a$.HCl$

b$.O_2$

c$.H_{2}S$

a$)$ Draw structural diagrams for the following molecular compounds. $($value $8)$

i$.C{H}_4$

ii$.H_{2}O$

iii. $N{H}_3$

iv$.C_2{H}_{5}OH$

b$)$ Give the shape of the following molecules $($linear$,$ pyramidal, tetrahedral or v$-$shaped$).($value $3)$

i$.C{H}_4$

ii$.H_{2}O$

iii. $N{H}_3$