What does adding a neutron to an atom's nucleus do to the atom's mass?
o
a. it adds 1 more unit of mass to the atomic weight of the atom.
b. a proton will be added with the neutron, increasing the weight by 2
mass units.
c. a neutron has no mass, so the atomic mass will remain
unchanged.
o
d. adding a neutron is balanced by adding an electron, keeping the
mass the same.

A :) It adds 1 more unit of mass to the atomic weight of the atom.

Explanation:

I just completed it on apex

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.