Question

The horizontal rows in Mendeleev's Periodic table are numbered from ____.

Answer 1

Mendeleev's periodic table

• “Mendeleev arranged elements in vertical columns and horizontal rows of a table in order of their increasing atomic weights in such a way that the elements with similar properties occupied the same vertical column or group.”
• The horizontal rows in Mendeleev's Periodic table are numbered from $1\text{to}12$.
• According to Mendeleev's Periodic table,these12 horizontal rows are called series.

The horizontal rows in Mendeleev's Periodic table are numbered from $1\text{to}12$.