Question

The first period has_____elements and was called as_____period in modern periodic table.

• A. two
• B. shortest

Answer 1

Modern periodic table:

• The modern periodic table is an arrangement of all the elements known in accordance with their increasing atomic number and recurring chemical properties.
• It is a tabular display of 118 chemical elements which consists of horizontal rows called periods and vertical columns are called groups.
• The first period in the modern periodic table has two elements in it that are Hydrogen and Helium, also it is the shortest period as all other periods have more elements in it.

So, the first period has two elements and was called as shortest period.