Question

Fill in the blanks
"1. The concept of grouping elements into triads was given by ……… .
2. Mendeleev’s basis for the Periodic Table is ……… .
3. The basis for Modern Periodic Table is ……… .
4. (a) Metallic character ……… down the group.
(b) Atomic size ……… along the period.
(c) Electronegative character ……… down the group.
5. Isotopes belong to the same ……… in the Periodic Table.
6. Halogens belong to group ……… of the Periodic Table.
7. An element having electronic configuration (2, 8, 2) belongs to the ……… group.
8. Atoms of different elements with the same number of occupied shells are placed in the same ……… .
9. Valency of elements ……… and then ……… as we move across the period while it remains the same down the group.
10. Non-metals are located on the ……… side of the Periodic Table."

Answer 1

Answer:

1.  Johann Dobereiner

2. The physical and chemical properties in the increasing order of the atomic       masses

3.The physical and chemical properties in the increasing order of the atomic number

4.(a).  increases

  (b).Atomic size gradually decreases from left to right across a period of elements

  (c). decreases

5. isotopes are at the same place on the periodic table

6. 17

7. 2nd group

8.  period

9.  increases then decreases

10. Right