Question

In Mendeleev’s periodic table, the vertical columns are called __________ and the horizontal rows are called _____________

Answer 1

Hint: We have to know that the periodic table is the tabular display of chemical elements. These elements are arranged in the increasing order of atomic number, electronic configuration and the chemical properties. Hydrogen is the element with the lowest atomic number and oganesson is the element with the highest atomic number. And the periodic table contains vertical columns and horizontal rows. The columns are going from top to bottom and the rows are going from left to right.

Complete answer:
We need to remember that the scientist Mendeleev arranged the elements in the periodic table in the increasing order of atomic mass. And in Mendeleev’s periodic table, the vertical columns are known as groups and the horizontal rows are known as periods. The number of groups and periods are eighteen and seven respectively. The elements with the same properties are arranged in the same group. Eg: lithium, potassium and rubidium are in the first group. The elements present in the same period have the same number of shells. But in the case of groups, the elements will gain the electrons and the number of shells increases.

Note:
We have to know that the elements are arranged in the increasing order of atomic masses and it contains seven periods and eighteen groups. Each period contains eight elements. The atomic mass is increasing from left to right in a period and all the elements present in the same element have the same number of shells. And the elements present in the same groups have similar properties.