Methane contributes towards global warming so it is called a _________________ gas.

 

White phosphorus undergoes spontaneous combustion when exposed to air. In order to prevent this spontaneous ignition, it is preserved under water. 

Sulphuric acid is called the King of Chemicals because it is used in the preparation of a very large number of other useful chemicals such as hydrochloric acid, nitric acid, dyes, drugs etc. In fact the annual production of shulpuric acid in a country is a measure of the economy of the country.

Atomic number is the serial number of an element in the periodic classification of elements. It gives the number of protons and also the number of electrons in an atom.

Sodium hydroxide - NaOH is caustic soda

Sodium carbonate - Na2CO3 is washing soda

Sodium bicarbonate - NaHCO3  is baking soda 

According to Bohr model, Each shell can occupy 2n2 electrons in their orbits where n=1,2,3.. for K,L,M,..

The atom has 2 electrons in k, 8 electrons in L and 7 electrons in M = 2 + 8 + 7 = 17

And given that its nucleus has 18 neutrons

=> its mass number = number of (electrons + neutrons ) = 17 + 18 = 35