Question

In the periodic table, elements are ordered in increasing 1 so that 2 of elements, fall into vertical columns. Of the four general categories of elements, calcium is a 3 element, nickel is a 4 , 5 and xenon are 6 . An element in Group II A, such as calcium, is also known as an 7 metal.

Answer 1

In a period, elements differ with only one electron which consecutively placed whereas in a group they have the similar configuration except for the difference in the outer most shell.
Calcium - $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^2$ s-block and p-block elements are called representative elements. Here Calcium is s-block element because the last electron is entering the s-orbital.
This calcium group elements are also known as alkaline earth elements because these are available in the earth more and alkali in nature as these are metals.
Nickel - $\left[Ar\right]3d^{9}4s^1$. It is a transition element as last electron is entering d orbital.

Helium - $1s^2$ & Xenon - $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{10}5s^{2}5p^6$. They have octet stable configuration, hence are called noble gas.

Hence, blanks are: (1) atomic number, (2) groups, (3) representative, (4) transition, (5) helium, (6) noble gas, (7) alkaline earth.