Question

question 3
listen
which of the following best describes a trait elements in the same period have in common?
a elements in the same period have the same number of electrons in their outermost shells.

b elements in the same period have the same number of energy levels housing their electrons.

c elements in the same period have the same number of valence electrons.

Explanation:

To determine the correct answer, we analyze each option:

• Option A: Elements in the same group (not period) have the same number of electrons in their outermost shells (valence electrons). So A is incorrect.
• Option B: In the periodic table, a period represents the number of energy levels (shells) that electrons occupy. For example, period 2 elements have electrons in 2 energy levels, period 3 in 3, etc. So elements in the same period have the same number of energy levels. This is correct.
• Option C: Valence electrons (outermost shell electrons) are the same for elements in the same group, not period. So C is incorrect.

Answer:

B. Elements in the same period have the same number of energy levels housing their electrons.