the red arrow is pointing to first energy level. on the periodic table, what is related to this level? a…

the red arrow is pointing to first energy level. on the periodic table, what is related to this level? a. 1st group (column) b. atomic number c. 1st period (row) d. atomic mass
Answer
Answer:
C. 1st period (row)
Explanation:
Step1: Understand energy - level concept
The first energy level is closest to the nucleus.
Step2: Relate to periodic - table
Elements in the first period have electrons in the first energy level.
Step3: Analyze options
A. 1st group has different energy - level filling patterns. B. Atomic number is the number of protons. D. Atomic mass is related to protons and neutrons. So, C is correct.