The 3d sublevel is not filled until after the 4s sublevel, because the 3d sublevel has more energy than the 4s sublevel, and less energy than the 4p sublevel. (:
The reaction is missing the Zn(s) in the reactants. The stoichiometry of the copper/zinc is 1 mole to 1 mole
Answer:
C.) 2
Explanation:
The pH equation is:
pH = -log[H⁺]
In this equation, [H⁺] is the molarity of the acid. In this case, the acid is HCl. Molarity can be found using the equation:
Molarity (M) = moles / volume (L)
Since you were given moles and volume, you can find the molarity of HCl.
Molarity = moles / volume
Molarity = 0.01 moles / 1.00 L
Molarity = 0.01 M
Now, you can plug the molarity of the acid into the pH equation.
pH = -log[H⁺]
pH = -log[0.01]
pH = 2
Answer:
Option B. 4.25×10¯¹⁹ J
Explanation:
From the question given above, the following data were obtained:
Frequency (f) = 6.42×10¹⁴ Hz
Energy (E) =?
Energy and frequency are related by the following equation:
Energy (E) = Planck's constant (h) × frequency (f)
E = hf
With the above formula, we can obtain the energy of the photon as follow:
Frequency (f) = 6.42×10¹⁴ Hz
Planck's constant (h) = 6.63×10¯³⁴ Js
Energy (E) =?
E = hf
E = 6.63×10¯³⁴ × 6.42×10¹⁴
E = 4.25×10¯¹⁹ J
Thus, the energy of the photon is 4.25×10¯¹⁹ J
Answer:
1.26*10²³ particles are present in 12.47 grams of NaCl
Explanation:
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023 * 10²³ particles per mole. The Avogadro number applies to any substance.
So, first of all you must know the amount of moles that represent 12.47 grams of NaCl. For that it is necessary to know the molar mass.
You know:
- Na: 23 g/mole
- Cl: 35.45 g/mole
So the molar mass of NaCl is: 23 g/mole + 35.45 g/mole= 58.45 g/mole
Now you apply a rule of three as follows: if 58.45 grams are present in 1 mole of NaCl, 12.47 grams in how many moles will they be?
moles= 0.21
You apply a rule of three again, knowing Avogadro's number: if in 1 mole of NaCl there are 6,023 * 10²³ particles, in 0.21 moles how many particles are there?
number of particles= 1.26*10²³
<u><em>1.26*10²³ particles are present in 12.47 grams of NaCl</em></u>
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