Question

9. Name two elements that you would expect to show
chemical reactions similar to calcium. What is the
basis of your choice ?
10. Name the (i) metals (ii) metalloids and (iii) non-metals
in the first twenty elements.
11. Fluorine, chlorine and Bromine are put in one group
on the basis of their similar properties.
(i) What are those similar properties ?
(ii) What is the common name of this group or family?
12. What is the main characteristic of the last element in
each period of the Periodic Table ? What is the
general name of such elements ?
13. According to atomic structure, what determines which
element will be the first and which will be the last in a
period?
14. How does the number of :
(i) valence electrons and
(ii) valency vary on moving from left to right in the
third period of the periodic table ?​

Answer 1

Explanation:

9) Beryllium and magnesium will show similar chemical reactions as calcium.

10)Lithium, Beryllium, Sodium, Magnesium, Aluminum, Potassium, and Calcium are metals out of the first 20 elements. 

Hydrogen, Helium, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Phosphorus, Sulfur, Chlorine, and Argon, are non-metals within the first 20 elements