Answer:
a. The letters Na with one dot
Explanation:
An atom can be defined as the smallest unit comprising of matter that forms all chemical elements. Thus, atoms are basically the building blocks of matters and as such determines or defines the structure of a chemical element.
Generally, atoms are typically made up of three distinct particles and these are protons, neutrons and electrons.
In Chemistry, electrons can be defined as subatomic particles that are negatively charged and as such has a magnitude of -1.
Valency can be defined as a measure of the combining power of a chemical element with other atoms to form a molecule or chemical compound.
Valence electrons can be defined as the number of electrons present in the outermost shell of an atom. Thus, valence electrons are used to determine whether an atom or group of elements found in a periodic table can bond with others.
Sodium is a chemical element that is found in group (1) of the periodic table and as such it has 1 electrons in its outermost shell. Also, the chemical symbol for Sodium is Na and it has one (1) valence electron.
A Lewis structure can be defined as a structural representation of an atom or molecule by using a dot to show the position and distribution of electron(s) around the atom or molecule.
Hence, the letters Na with one (1) dot is a correct Lewis structure diagram for Sodium (Na) because it has just one (1) valence electron in outermost shell.
For example, the Lewis structure diagram for Sodium (Na) is •Na.
