Question

Name an element which has twice as many electrons in its second shell as in the first shell.

Answer 1

Step-1: Introduction

The elemental arrangement in periodic table into groups and periods is known as modern period table. The horizontal rows are periods while vertical columns are groups.

There are 7 periods and 18 groups in periodic table.

The outermost shell is the valence shell of the element. The elements in groups have similar electronic configuration of the valence shell.

The given element contains 2 electrons in the first shell and 4 electrons in the outermost shell.

Step-2: To find the group of element

Number of valence electrons in the valence shell = 4

Number of valence electrons + 10= Number of group

So, the element belong to group 14.

Step-3: To find the period of element

Number of valence shell = 2

Number of valence shell = Number of period

So, the element belong to period 2.

Therefore, the element that has two shells and four valence electrons is Carbon ($\mathrm{C}$).

Carbon belongs to period 2 and group 14.

Final answer

Therefore, element that has twice as many electrons in its second shell as in the first shell is Carbon.