Answer:
A) a chain reaction that is caused by nuclear fission
Explanation:
nuclear fusion yields more energy than nuclear fission and the products of the reaction are not radioactive
69.9%
Explanation:
To find the mass percentage of iron in the compound in Fe₂O₃, we would go ahead to express the given molar mass of the iron to that of the compound.
Mass percentage = 
x 100
Molar mass of Fe = 55.85g/mol
Molar mass of O = 16g/mol
Molar mass of Fe₂O₃ = 2(55.85) + 3(16) = 159.7g/mol
Mass percentage = 
= 69.94% = 69.9%
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Mass percentage brainly.com/question/8170905
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The chemist the count the number of particles (Atoms, Molecules or Formula Unit) in a given number of moles of a substance by using following relationship.
Moles = # of Particles / 6.022 × 10²³
Or,
# of Particles = Moles × 6.022 × 10²³
So, from above relation it is found that 1 mole of any substance contains exactly 6.022 × 10²³ particles. Greater the number of moles greater will be the number of particles.
