Boron cannot form which one of the following anions?

(1) BO2-

(2) BF63-

(3) BH4-

(4) B(OH)4-

Which of the following statements is INCORRECT?

I) Bleaching powder is a pale yellow powder

II) Dry NH3 gas turns red litmus blue

III) The pH of rain water is nearly 7

IV) The pH of acid rain is nearly 5.6

There are 15 protons and 22 neutrons in the nucleus of an element. What is its mass number?

The element with the highest electron affinity among halogens is

An unbalanced chemical equation is called a

When large quantities of ___ are consumed, it tends to slow metabolic processes and to depress the central nervous system.

When iron is exposed to moist air, a reddish brown coating of hydrated Iron (III) Oxide (Fe2O3) is deposited on its surface. This reddish brown coating is called

In the Modern Periodic Table elements present in the same period will have the same

Plaster of Paris ______.

I. changes into gypsum on mixing with water

II. is CaSO4.2H2O

III. is used for decoration