Question

Which statement about the properties of some elements is correct?

A. All noble gases are unreactive
due to having eight electrons in their outer shells.

B. The Group VII element astatine, Atz, is expected to be a black solid at room temperature.

C. The reactivity of the elements in both Group I and Group VII increases down the group.

D. When aqueous chlorine is added to aqueous potassium bromide there is no change in
color.​

Answer 1

Answer:

Halogen, any of the six nonmetallic elements that constitute Group 17 (Group VIIa) of the periodic table. The halogen elements are fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). They were given the name halogen, from the Greek roots hal- (“salt”) and -gen (“to produce”), because they all produce sodium salts of similar properties, of which sodium chloride—table salt, or halite—is best known.