Question

how can the periodic table of elements be used to find the number of electrons in an element?
o a. the atomic mass tells how many electrons are in an element.
o b. elements in the same group have the same number of electrons.
o c. elements in the same period have the same number of electrons.
o d. the atomic number tells how many electrons are in an element.

Explanation:

• Option A: Atomic mass is the sum of protons and neutrons, not related to electron count.
• Option B: Elements in the same group have the same number of valence electrons, not total electrons.
• Option C: Elements in the same period have the same number of electron shells, not total electrons.
• Option D: For a neutral atom, the atomic number (number of protons) equals the number of electrons.

Answer:

D. The atomic number tells how many electrons are in an element.