choose five elements from the periodic table and arrange them according to increasing atomic radii increasing ionization energy increasing electronegativity in increasing metallic property​

Solubility would be your answer.

Electrons are emitted

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).

The answer is d- principle of faunal succession.