Question

1. choose the best answer.

how do you determine the number of energy levels an element has by looking at the periodic table of elements?
it is the same number as the period number.
it is the same number as the last digit of the group number.
it is the same as the atomic number.
it is the same as the atomic mass.

1. choose the best answer.

francium is in period 7 and group 1 and has an atomic number of 87. how many energy levels does francium have?
80
1
87
7

Explanation:

• For question 7: In the periodic table, the number of energy levels (electron shells) an element has is equal to its period number. For example, elements in period 2 have 2 energy levels.
• For question 8: Since francium is in period 7, using the rule from question 7 (number of energy levels = period number), it has 7 energy levels.

Answer:

1. It is the same number as the period number.
2. 7