Question

Fill in the blanks from the choices given below. a. Do not bring any ________ near hydrogen as the gas is explosive in nature. [naked flame/ cell phone] b. Most of the elements tend to be inactive if they have in their valence shell _________. [ 2 electrons/ 8 electrons] c. Some carbon atoms have mass number 12 and some have mass number 14. These atoms of different mass numbers are called ____________. [ Isobars/ Isotopes] d. Atomic number of an element is 9. Its valency is _________. [+1/-7/-1] e. A chemical reaction which proceeds with the absorption of ________ energy is called photochemical reaction. [Electric/ light] *

Answer 1

Answer:

1 naked flame

2 2 electrons

3 isotopes

4 -1

5 light energy