Which best describes the bond that would form between lithium (li) and fluorine (f)?
they form a covalent bond by exchanging four electrons.
they form a covalent bond by sharing three electrons.
they form an ionic bond by exchanging four electrons.
they form an ionic bond by exchanging one electron.

The correct answer is they form an ionic bond by exchanging an electron.

Explanation: There are 2 types of bond that can be formed between the elements.

1. Ionic bond: These bonds are formed when there is a complete transfer of electrons from one element to another. The element which donates an electron is a n electropositive element and an element which accepts an electrons is an electronegative element.

2. Covalent bond: These bonds are formed when there is sharing of electrons between two elements.

Lithium is the 3rd-element of the periodic table having electronic configuration:

This element can easily loose 1 electron.

Fluorine is the 9th-element of the periodic table having electronic configuration:

This element can easily accept 1 electron.

Hence, these elements form ionic bond because there is complete transfer of electrons from lithium to fluorine. As, only 1 electron is getting transferred from lithium to fluorine. Therefore, the correct answer is they form an ionic bond by exchanging an electron.

answer:

sequence 1- deletion

                  2- duplication

                  3- insertion

                  4- substitute

                  5- inversion