Respuesta :
The correct answer would be the third option. The chemical properties cycle through each period because the atoms' outermost shells having two or more electron shells cannot have more than eight electrons. This is following the octet rule.
Answer: Option (d) is the correct answer.
Explanation:
A period is represented by a horizontal line as we move from left to right in a periodic table.
Since, number of electrons keep on adding into the elements while we move in a period. Therefore, number of valence electrons also increases in a period and when the valence shell of last element of a period gets completely filled then the cycle repeats itself.
And elements with same number of valence electrons will show same chemical properties.
Thus, we can conclude that the chemical properties cycle through each period because each period represents a cycle of completing the outer electron shell.
