Answer:
Al: 3
S: 6
Explanation:
Al is in Group III. This means that it has 3 valence electrons.
S is in Group VI. This means that it has 6 valence electrons.
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782g
Explanation:
Given parameters:
Number of moles of N₂ = 23moles
Unknown:
Mass of NH₃ = ?
Solution:
We first obtain the balanced chemical equation for this reaction;
N₂ + 3H₂ → 2NH₃
From the equation we see that;
1 mole of N₂ produced 2 moles of ammonia
23 mole of N₂ will yield 2 x 23 = 46moles of ammonia
Now ;
mass of ammonia = number of moles x molar mass
Molar mass of NH₃ = 14 + 3(1) = 17g/mol
Mass of ammonia = 46 x 17 = 782g
learn more:
Number of moles brainly.com/question/1841136
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Its D. 13-14 billion years
Answer is: the average atomic mass of 125 atoms of uranium is 235.88.
ω(U-234) = 10 ÷ 125.
ω(U-234) = 0.080.
ω(U-235) = 75 ÷ 125.
ω(U-235) = 0.60.
ω(U-238) = 40 ÷ 125.
ω(U-238) = 0.320.
Average atomic mass of atoms of uranium =
Ar(U-234) · ω(U-234) + Ar(U-235) · ω(U-235) + Ar(U-238) · ω(U-238).
Average atomic mass of atoms of uranium =
234 · 0.08 + 235 · 0.6 + 238 · 0.32.
Average atomic mass of atoms of uranium = 18.72 + 141 + 76.16.
Average atomic mass of atoms of uranium = 235.88.