Question

question 17 (5 points)
listen
a group in the periodic table has the same
a) shell number.
b) number of neutrons.
c) number of outer shell electrons.
d) number of protons.

Explanation:

• Option A: Shell number (principal quantum number) is the same for elements in a period, not a group. So A is incorrect.
• Option B: The number of neutrons varies among isotopes of an element and is not consistent within a group. So B is incorrect.
• Option C: Elements in the same group of the periodic table have the same number of valence (outer shell) electrons, which determines their chemical properties. So C is correct.
• Option D: The number of protons is the atomic number, and each element has a unique atomic number, so elements in a group have different numbers of protons. So D is incorrect.

Answer:

C. number of outer shell electrons.