Sponge
Chlorine
Polythene
Sulphur
The substance that is least prone to catch and spread fire is
The temperature of oxy-acetylene flame is around
The term meaning copper demon denotes the metallic element
The third shell of an atom can have a maximum of _ electrons.
The three elements most needed in common fertilisers are:
The two metal ions that cause hardness to water are:
The uranium fuel used worldwide is mainly in the form of
The working of a dry cell is based on
There are two elements calcium (atomic number 20) and argon (atomic number 18) The mass number of both the elements is 40. They are therefore known as
Thermal electricity is generated by using which of these ?
