Question

describe the periodic nature and properties of atoms and molecules.

Explain at a level of detail Dmitri Mendeleev would have understood how halogens and alkali metals are extremely reactive, whereas noble gases are not reactive.

Compare properties of molecules formed from atoms in similar families; for example, H₂S versus H₂O.

Explain what is meant by the electronic structure of atoms. How does knowing the electronic structure of atoms aid chemists in predicting chemical reactions?

Answer 1

(1) Dmitri Mendeleev was a chemist who developed the periodic classification of elements.He understood that the reason why alkali metals and halogens were so reactive because they had one electron in their outer shell.It takes a small amount of energy to gain or to lose the one eletron.The opposite can be said when dealing with noble gases. They are not reactive because of their valence shell. All of their valence shell is full which is responsible for non reactive nature of noble gases.

(2) The chemical propeties of oxygen and sulphur are alike because of both of them have six electrons in their electronic shell. Each of these elements form molecules with two hydrogens. Those ae water and hydrogen sulphide.Hydrogen sulphide is not strong like water whihc causes its low melting and boiling points,.

(3) Predicting of chemical reactions can be done by understanding electronic structure of atoms. The arrangement of electrons in the valence shell of atoms will cause its chemical behaviour.