Answer:
10.3 g Al
Explanation:
To find the excess mass of Al, you need to (1) convert grams I₂ to moles I₂ (via molar mass), then (2) convert moles I₂ to moles AlI₃ (via mole-to-mole ratio from equation coefficients), then (3) convert moles AlI₃ to grams AlI₃ (via molar mass). Now that you have the actual amount of AlI₃ produced, you need to (4) convert grams AlI₃ to moles AlI₃ (via molar mass), then (5) convert moles AlI₃ to moles Al (via mole-to-mole ratio from equation coefficients), and then (6) convert moles Al to grams Al (via molar mass). Now that you know the amount of Al actually needed to produce the product, you need to (7) find the excess mass of Al.
Molar Mass (Al): 26.982 g/mol
Molar Mass (I₂): 2(126.90 g/mol)
Molar Mass (I₂): 253.8 g/mol
Molar Mass (AlI₃): 26.982 g/mol + 3(126.90 g/mol)
Molar Mass (AlI₃): 407.682 g/mol
2 Al(s) + 3 I₂(g) -------> 2 AlI₃(g)
113 g I₂ 1 mole 2 moles AlI₃ 407.682 g
------------- x ---------------- x ---------------------- x ------------------- = 121 g AlI₃
253.8 g 3 moles I₂ 1 mole
121 g AlI₃ 1 mole 2 moles Al 26.982 g
--------------- x ------------------ x --------------------- x ----------------- = 8.01 g Al
407.682 g 2 moles AlI₃ 1 mole
Starting Amount - Mass Needed = Excess
18.3 g Al - 8.01 g Al = 10.3 g Al
Leading up to this, calcium gave up 2 valence electrons and thus was denoted as a cation. These 2 electrons were transferred to bromine, which received an overall negative charge because of the addition of 2 valence electrons in its valence shell, and thus formed a negatively charged ion, an anion.
Both formed an ionic bond, due to the electrostatic charge of attraction between the 2 oppositely charged ions. If many ions of Ca and Br are present and numerous ionic bonds have formed it will undergo an arrangement which is that of an ionic lattice, type of structure.
Answer:
X = ²³⁵₉₂U
Explanation:
Nuclear equation:
²³⁹₉₄Pu → ²³⁵₉₂U + ⁴₂He
The isotope of plutonium-239 undergo alpha decay and produced uranium-235.
Alpha decay:
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom the starting atom.
Properties of alpha radiation:
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴