Question

write any three features of Mandeleev's periodic table.​

Answer 1

Explanation:

The periodic table is composed of seven horizontal rows or periods and is numbered between 1 and 7. There is a regular gradation in the properties of elements in the horizontal rows(periods) from left to right. The periodic table is composed of eight vertical columns or groups. They 're numbered between 1 to 8.

Answer 2

Answer:

1) In Mendeleev periodic table, vertical columns in the periodic table and horizontal row in the periodic table were named as groups and period respectively.

2) The periodic table is composed of seven horizontal rows or periods and is numbered between 1 and 7.

3) There is a regular gradation in the properties of elements in the horizontal rows(periods) from left to right

Explanation: