(a) An element X has mass number 40 and contains 21 neutrons in its atom. To which group of the periodic table does it belong ?

(b) The element X forms a compound X2Y. Suggest an element that Y might be and give reasons for your choice.

4 views

1 Answers

(a) Group 1 (2, 8, 8, 1).

(b) Oxygen (X is monovalent so Y has to be divalent to form the compound X2Y)

4 views