Answer the following questions regarding Mendeleev’s modified Period

1.	Answer the following questions regarding Mendeleev’s modified Periodic Table.(i) In which vertical column hydrogen is placed. (ii) What are horizontal rows known as ? How many are they in number? (iii) How many elements are there in the first horizontal row? (iv) How many elements are there in the second and third horizontal rows each?
Answer» (i) Hydrogen is placed in IA group. (ii) The horizontal rows in Periodic Table are known as periods. There are seven periods in all. (iii) There are only two elements in the first period. (iv) The second and third periods have eight elements each.

Answer the following questions regarding Mendeleev’s modified Periodic Table.(i) In which vertical column hydrogen is placed. (ii) What are horizontal rows known as ? How many are they in number? (iii) How many elements are there in the first horizontal row? (iv) How many elements are there in the second and third horizontal rows each?

Answer»

(i) Hydrogen is placed in IA group.

(ii) The horizontal rows in Periodic Table are known as periods. There are seven periods in all.

(iii) There are only two elements in the first period.

(iv) The second and third periods have eight elements each.