What is the total number of neutrons in an
atom of Li?
A. 7
B. 10
C. 3
D. 4

Explanation:

The neutrons in an element can be found by subtracting the atomic number from the atomic mass.

Li is the symbol for lithium.

This element has an atomic mass of 6.941, which we can round to 7.

Lithium's atomic number is 3.

Lithium has a total number of 4 neutrons.

D)4

Explanation:

Lithium is an alkali metal with the atomic number = 3 and an atomic mass of 6.941 g/mol. This means that lithium has 3 protons, 3 electrons and 4 neutrons (6.941 - 3 = ~4).

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."