how can the position of carbon in the reactivity series of metals determine the extraction of metals from their ores or metallic compounds?? pls urgentt​

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

The two naturally occurring isotopes of chlorine are 35cl (34.969 amu, 75.77%) and 37cl (36.966 amu, 24.23%). the two naturally occurring isotopes of bromine are 79br (78.918 rm amu, 50.69%) and 81br (80.916 amu, 49.31%). chlorine and bromine combine to form bromine monochloride, brcl. 1. how many peaks will be present in a mass spectrum for brcl? the four combinations of molecule possible given these four isotopes are: 81br37cl, 81br35cl, 79br37cl, and 79br35cl. 2. what are the masses of the four different brcl molecules? express the masses using six significant figures, in decreasing numeric order (highest to lowest), separated by commas.

Chris is about to do an experiment to measure the density of water at several temperatures. his teacher has him prepare and sign a safety contract before beginning the experiment. which term is mostlikely part of the safety contract