Which of the following groups have seven valence electrons and are very reactive? (2 points) select one: a. column 1 alkali metals b. column 2 alkaline earth metals c. column 17 halogens d. column 18 noble gases

option (c). column 7 halogens groups have seven valence electrons and are very reactive in nature.

explanation:

halogens are group of elements having seven electron in their outermost or valance shell and they need only one electron to become stable and attain the electronic configuration of noble elements. that's why halogens are more reactive in nature. e.g are flourine, chlorine and iodine etc.

identify the dna change shown in the diagram and explain how that change can result in the increased genetic diversity often seen among siblings.identify the dna change shown in the diagram and explain how that change can result in the increased genetic diversity often seen among siblings.v

answer: b

coz red blood cells marrow and circulates the body for 120 days.