Based on their positions in the periodic table, which two elements would most readily combine to make a stable compound? A. hydrogen (H) and lithium (Li) B. sodium (Na) and magnesium (Mg) C. helium (He) and neon (Ne) D. sodium (Na) and chlorine (Cl)

D. Sodium and Chlorine

Sodium has 1 electron and Chlorine has 7 electrons. For a compound to be stable, they must have 8 electrons. NaCl = 8 electrons

Fun Fact - You eat NaCl everyday. It's table salt which you put in food.

Answer: Option (D) is the correct answer.

Explanation:

For two elements to be stable in nature, there must be need of an element to gain an electron and there must be need of another combining atom to lose an electron.

In case of hydrogen and lithium, hydrogen has only one electron whereas lithium has 3 electrons. When both of them chemically combine together then they will form LiH.

In case of sodium and magnesium, both of then are metals and therefore, both of then need to lose electrons in order to gain stability. Hence, there will be no formation of bond between them.

In case of helium and neon, both of them have completely filled octet. So, they neither need to gain or lose an electron because they are already present in their stable state. Hence, they do not combine with each other.

In case of sodium and chlorine, sodium has one valence electron and chlorine has 7 valence electrons. So, in order to attain stability sodium will transfer its one electron to the chlorine atom.

As a result, there will be formation of ionic bond will take place. Also, when we move down the group there will be decrease in ionization energy of the metals.

Hence, sodium will lose an electron more easily than lithium.

Thus, we can conclude that sodium (Na) and chlorine (Cl) lements would most readily combine to make a stable compound.