What is the mass number of an element if its atom contains 10 protons, 10 electrons and 12 neutrons?

The type of chemical bond that exists between potassium and oxygen in potassium oxide is

Elactrostatic force of attraction between sodium ion and halide ion is greatest in

Which of the following contains co-ordinate covalent bond?

Which of the following non-metals reacts most readily with metals?

Chlorine atom forms CI by

An element Z has a combining power of 3. Which of the following formulae is correct of its compounds?

Electrovalent compounds are characterized by

The atoms of four elements are represented as 20Q, 16R, 10S and 8T Which of the elements would be unreactive?