What is ammonia $(NH_3)$?

$(a)$ Amongst the following elements,identify the ones that would form anions:
$K, O, Na, F, Ca, Cl, Mg$
$(b)$ Write the electronic configuration of the anions identified above.

What is the molecular formula of phosphorus pentoxide?

An element $X$ (atomic number $17$) reacts with an element $Y$ (atomic number $20$) to form a divalent halide.
$(a)$ Where in the periodic table are elements $X$ and $Y$ placed?
$(b)$ Classify $X$ and $Y$ as metal$(s)$,non-metal$(s)$,or metalloid$(s)$.

Write the electron dot structures of magnesium and chlorine and show the formation of magnesium chloride by the transfer of electrons.

An electrolytic cell consists of
$(i)$ positively charged cathode
$(ii)$ negatively charged anode
$(iii)$ positively charged anode
$(iv)$ negatively charged cathode