The average atomic mass of an element can be determined by multiplying the individual masses of the isotopes with their respective relative abundances, and adding them.
Average atomic mass of Br = 158 amu(0.2569) + 160 amu(0.4999) + 162 amu(0.2431)
Average atomic mass = 159.96 amu
As described in the problem, the relative abundance for Br-79 is 25.69%. This is because 2 atoms of Br is equal to 79*2 = 158 amu. Similarly, the relative abundance of Br-81 is 81*2 = 162, which is 24.31%.
Number of molecules NH₃ = 4.45 x 10²²
<h3>Further explanation
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A mole is a number of particles(atoms, molecules, ions) in a substance
This refers to the atomic total of the 12 gr C-12 which is equal to 6.02.10²³, so 1 mole = 6.02.10²³ particles
Can be formulated :
N = n x No
N = number of particles
n = mol
No = 6.02.10²³ = Avogadro's number
mol of NH₃ = n = 0.074
So the number of molecules :

Iron and chlorine
For every iron there are 3 chlorine.
Answer:
449.5 g
Explanation:
Silver sulfate- Ag2SO4
M(Ag)=107 g/mol => M(Ag2)=214 g/mol
M(S)=32 g/mol
M(O)=16 g/mol => M(O4)=64 g/mol
M(Ag2SO4)=310 g/mol
n=1.45 mol
m(Ag2SO4)=M(Ag2SO4)*n=310 g/mol *1.45 mol= 449.5 g
Answer:
Conduction, Convection and Conduction
Explanation: