Question

What does the period number tell about the energy levels are occupied by the electrons in an atom?

A-The period number tell us how many electrons are in the highest energy level of the atom

B-The period number tell us how many electrons are in each sub level of the atom

C-The period number tells how many energy sub levels are occupied in the atom

D-The period number tells which is the highest energy level occupied by the electrons

Answer 1

Answer: Option (D) is the correct answer.

Step-by-step explanation:

When we move across a period then electrons in atoms keep on adding in the same sub-shell.

And, with increase in number of shells there will also occur increase in energy level of the electrons.

For example, elements present in row two have n = 2. That is, the highest energy levels occupied by the electrons of elements of row two is 2.

Similarly, for elements of row 3 the value of n = 3 and so on. Hence, with increase in row number there will also occur an increase in energy level of the atoms.

Therefore, we can conclude that the period number tells which is the highest energy level occupied by the electrons in an atom.

Answer 2

C-The period number tells how many energy sub levels are occupied in the atom

Step-by-step explanation:

In the Periodic Table of Elements, the periods are the horizontal rows. As such, Hydrogen and Helium are in the first period, while Lithium and Beryllium are in the second period.

Moving down in the periodic table the energy sub-levels occupied in the atom increase, Sodium has one more occupied energy sub-level than Beryllium, and Beryllium has one more occupied energy sub-level than Hydrogen.