Write true or false for the statement: It was assumed by Newlands that only $63$ elements existed in nature and no more elements would be discovered in the future.

Three elements $B, Si$ and $Ge$ are:

An element $X$,which is a yellow solid at room temperature,shows catenation and allotropy. $X$ forms two oxides which are also formed during the thermal decomposition of ferrous sulphate crystals and are major air pollutants.
$(a)$ What would be the nature (acidic/basic) of the oxides formed?
$(b)$ Locate the position of the element in the Modern Periodic Table.

Which of the following sets of elements is written in the order of their increasing metallic character?

What type of oxide would Eka-aluminium form?

$(a)$ Electropositive nature of the element$(s)$ increases down the group and decreases across the period.
$(b)$ Electronegativity of the element decreases down the group and increases across the period.
$(c)$ Atomic size increases down the group and decreases across a period (left to right).
$(d)$ Metallic character increases down the group and decreases across a period.
On the basis of the above trends of the Periodic Table,answer the following about the elements with atomic numbers $3$ to $9$:
$(a)$ Name the most electropositive element among them.
$(b)$ Name the most electronegative element.
$(c)$ Name the element with the smallest atomic size.
$(d)$ Name the element which is a metalloid.
$(e)$ Name the element which shows maximum valency.