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Answer:
elements in same group have same valence electron.
period of element is equal to valence shell
Explanation:
if the elements are in a same group then they will be having same number of valence electron.
the period of an element in periodic table is equal to the valence shell of the element. that is if the valence electron are in 3 rd shell then the element will be in third period.
It is true that the iron recommendation for girls exceeds that of boys during adolescence.
During an adolescence, girls and boys require iron for a large growth spurt and the gain of adult phenotypes and biologic rhythms.
In this period of the life, iron recommendation increase in both girls and boys, because of the increase in lean body mass, the expansion of the total blood volume, the increase and start of menstruation at girls.
Iron is essential for oxygen transport, red blood cell creation, cognitive performance and immunological function.
The overall iron requirements for girls are up to twice as boys.
More about adolescence: brainly.com/question/13528489
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Electron affinity for fluorine is than chlorine most likely , due to the electron repulsion that occur between the electron where n= 2 . the elements in the second period have such small electron clouds that electron repulsion is greater than that of the rest of the family.
