The atomic symbol mc025-1.jpg represents potassium-40 (k-40), a radioactive isotope that has 19 protons and 21 neutrons. which atomic symbol could represent an isotope that results from the decay of k-40?

a) 40 ar
18

b) 40 k
18

c) 42 ca
20

d) 42 k
20

What substance has a mass of 9.5g and volume of 2.1cm^3

What does a complete balanced chemical equation include? a. exothermic coefficients b. endothermic coefficients c. valence electrons d. molar coefficients

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.