Out of the options, the best indicator is a color change since it is the only one that can't really be blamed on a physical change. you will eventually notice that during qualitative labs and some quantitative labs, usually the thing that you are looking for is either color change or the production of a precipitate to indicate the presence of a chemical reaction
Answer:

Explanation:
Iron is Fe, nitrogen is N. Nitrogen is diatomic, which means it occurs as a molecular pair by itself. Iron III nitride has a chemical formula of FeN because nitrogen has a charge of 3-, and iron III tells us the iron has a charge of 3+ so you just need one of each to make the charges balance and the compound neutral.
Greater than 23mcg/dl is considered a high level of morning cortisol.
Normally, cortisol levels rise during the early morning hours and are highest about 7AM. They drop very low in the evening and during the early phase of sleep. If you do not have this daily change (diurnal rhythm) in cortisol levels, you may have overactive adrenal glands. This condition is called Cushing's syndrome.
No, I don’t think so. My reason being that some of these viruses are not harmful, an example is bacteriophage which kills bacteria.
Well the elements would be N, P, As, Sb, and Bi. Their electron configuration would be N= [He] 2s2 2p3, P= 1s2 2s2 2p6 3s2 3p3, As= [Ar] 3d10 4s2 4p3, Sb= Kr 4d10 5s2 5p3, and Bi= Xe 4f14 5d10 6s2 6p3.<span />