Answer:
C) 4.
Explanation:
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In this case, since the electron configuration of nickel at its ground-state, considering 28 as its atomic number and the number of electrons it has in one atom, is:

We can see it has four energy levels, 1, 2, 3 and 4, which are related to the following principal quantum number, that describes the energy of an electron in the atom and its most probable distance with respect to the nucleus.
Therefore, nickel has C) 4 different principal quantum numbers.
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Answer: Marcia made a more concentrated salt solution.
Explanation:
Marcia used 1 kg of salt, which the exercise tells us is 2.2 lb.
She dissolved it in 3L of water, so we have to find out how much that is in pints. We do that using cross multiplication.
If 1L equals 2.11 pints, then
xpints / 3L = 2.11pints / 1L, so
xpints = (3L . 2.11pints) / 1L = 6.33 pints
Now we know she dissolved 2.2lb in 6.33 pints of water. We use cross multiplication again to find out how much salt she would have in 10 pints, so we can know how concentrated it is compared to Bobby's solution, which is 10 pints.
xlb / 10pints = 2.2lb / 6.33pints
xlb = (10pints . 2.2lb) / 6.33pints = 3.47lb
So Marcia has a concentration of 3.47lb per 10 pints, whereas Bobby only has 3lb per 10 pints.
<span>According to its definition, the answer is: The characteristics that best describe the tail of a phospholipid molecule are </span><span>a. neutral charge, nonpolar, and hydrophobic</span>
1) Reaction: 3Mg + N₂ → Mg₃N₂.
m(Mg) = 0,225 g
n(Mg) = 0,225 g ÷ 24,3 g/mol = 0,009 mol.
n(Mg) : n(N₂) = 3 : 1
n₁(N₂) = 0,003 mol.
n₂(N₂) = 0,5331 ÷ 28 = 0,019 mol.
n₃(N₂) = 0,019 mol - 0,003 mol = 0,016, m(N₂) = 0,016mol·28g/mol=0,4467g.
or simpler: m(N₂) = 0,225 g + 0,5331 - 0,3114 g = 0,4467 g.
2) Answer is: 6 <span>of fluorine atoms are combined with one uranium atom.
</span>m(U) = 209 g.
m(F) = 100 g.
n(U) = m(U) ÷ M(U)
n(U) = 209 g ÷ 238 g/mol.
n(U) = 0,878 mol.
n(F) = m(F) ÷ M(F)
n(F) = 5,263 mol
n(U) : n(F) = 0,878 mol : 5,263 mol /:0,878.
n(U) : n(F) = 1 : 6.
n - amount of substance
Answer:
M = 3.69 M.
Explanation:
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In this case, according to the given information, it turns out possible for us to calculate the molar concentration of the 1.29 moles of KCl in 350 mL of solution by recalling the mathematical definition of molarity as the division of the moles by the volume in liters, in this case 0.350 L; thus, we proceed as follows:

Which gives molar units, M, or just mol/L.
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