Elements are placed into the same period on the periodic table of the elements because they
question 1 options:

form the same type of chemical bonds.

form the same type of isotopes.

have the same chemical properties.

have the same number of electron energy levels.

Elements are placed into the same period on the periodic table of the elements because they _have the same number of electron energy levels..

Explanation:

The horizontal lines in the periodic table are called periods. Two elements that are in the same period, have the same amount of levels with electrons in their envelope. Example in period 2 are Nitrogen and Oxygen

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the darker peppered moth species were favored due to the fact that the industrial revolution had made all the nearby trees a darker color instead of white.