Which of the following pairs is/are correctly matched?

1. Isotopes: Atoms with same atomic number but different atomic mass
2. Isobars: Atoms with same number of neutrons but different atomic number
3. Isotones: Atoms with same mass number but different atomic number

Select the correct answer using the code given below:

Which one among the following is correct regarding ²⁰Ne, ²³Na⁺, ¹⁹F^- and ²⁴Mg²⁺?

During explosion of gunpowder, which of the following gases are evolved in the proportion of 1 : 3?

The metal constituent of chlorophyll is

The reaction that takes place in soap making is called saponification. Basically soap is sodium or potassium salts of

When a copper rod is dipped in aqueous silver nitrate solution, the colour of the solution changes to blue. This is because