Chemistry Questions

___ is the number of shells for elements of the 3rd period.

When formaldehyde and potassium hydroxide are heated , we get 

Generally covalently bonded molecules ______.

I. have high boiling and melting point as compare to ionically bonded molecules

II. poor conductors of electricity

III. have weak intermolecular force

Which is not a green house gas in the following?

Lime water becomes white due to which gas?

Name the Scientist who stated that matter can be converted into energy

Carbon dioxide is one of the gases that cause the _________.

Elements having same atomic numbers but different mass number are called ______.