Question

How does a lithium cation compare to a lithium atom?

Answer 1

Lithium cation and Lithium atom can be compared as follow;

1) Charge:

              The charge on Lithium atom is zero means, it has same number of protons and electrons. Hence, the nert effect is cancelled out and the atom gets zero charge.

               On the other hand, Lithium cation is formed when it looses one electron. Therefore, the number of protons are greater by one number as compared to number of electrons resulting in the formation of +1 charge as shown below,

                                                Li    →    Li⁺¹  +  e⁻

2) Size:

           Secondly, Lithium atom has greater size as compared to Lithium cation because due to presence of greater number of protons compared to electrons in Lithium cation the nuclear charge appears to be greater as compared to neutral atom hence, pulling the valence electrons more effectively making the lithium cation smaller in size as compared to neutral atom.

3) Reactivity:

                     We can also compare the reactivity of both species. The neutral will be more reactive than the charged atom because it is containing one valence electron and can donate it when ever it comes in contact with non-metals.

Answer 2

Hi Destromceler!

A lithium cation ion is smaller than a lithium atom. In lithium cation it has lost electrons, which causes the remaining electrons to be pulled in stronger by the positive charge in the nucleus. As they get closer to the nucleus decreases the overall size of the atom.

The bigger they are (the more electrons it has) the less effective the proton's pull will be. So if we were talking about a lithium anion (where electrons are gained) then it would be bigger than a lithium atom.