Write true or false for the statements: Non-metals are electronegative. They tend to form bonds by gaining electrons. As the trends in the electronegativity show,non-metals are found on the right-hand side of the periodic table towards the top.

Which of the following is the outermost shell for elements of period $2$?

An element $X$ belongs to the $3rd$ period and group $16$ of the Modern Periodic Table.
$(a)$ Determine the number of valence electrons and the valency of $X$.
$(b)$ Write the molecular formula of the compound formed when $X$ reacts with hydrogen and draw its electron dot structure.
$(c)$ Name the element $X$ and state whether it is metallic or non-metallic.

Why does atomic size decrease as we move from left to right along a period in the periodic table?

$(a)$ 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.

State the Modern Periodic Law.