Why does a lithium atom develop a positive charge?

Answer 1

Lithium only needs to lose one electron (and thus become positive) to achieve the same electron configuration as Helium which is extremely stable. The other option would be to gain 7 electrons to become like Neon which would be very energetically unfavorable.

Answer 2

Lithium is a metal in group 1A in the Periodic Table so it has 1 electron in the outer energy level so the and it has very weak nuclear attraction so it loses electron forming positive ion called Lithium cation.

Answer 3

Chemical reactions take place because atoms acquire greater stability by having a complete outer electron shell, which for most elements will mean having 8 electrons in the outer shell, but which for a few of the lightest elements, means having 2 electrons in the outer shell. The element lithium has a single electron in its outer shell, and if it loses that electron that leaves it with a complete inner shell (which then becomes the outer shell) of two electrons. In order to complete it existing shell by acquiring more electrons rather than losing the one it has, it would need to acquire another 7 electrons. That would be massively unstable, because electrons all repel each other, having negative charges (like charges repel) and there are not enough positively charged protons in the lithium nucleus to hold onto such a large number of extra electrons. It is much easier for lithium to lose one electron than it is to gain 7 electrons. So it loses an electron, by donating it to an atom that needs more electrons, such as oxygen, which needs two electrons to complete its outer shell (it starts out with 6 electrons in its outer shell).

And when lithium loses an electron it will then have one more proton than electrons, and as a result, it will have a positive charge.