Answer:
d. The limiting reactant is Br2, and 0.13 mol Al should remain unreacted.
Explanation:
From the reaction, 2Al(s) + 3Br2(l) → 2AlBr3(s)
2 moles of Al combines with 3 moles of Br to form 2 moles of AlBr3
Hence 1 mole of Br combines with 2/3 moles of Al
or 0.4 moles of Br combines with 2/3×0.4 moles of Al or 0.267 Moles of Al leaving
0.4 - 0.267 = 0.133 moles of Al remaining unreacted
election circles the nucleus
Answer:
n = 2.208x10¹⁸ photons
Explanation:
The energy of a photon( an elementary particle) is given by the equation:
E = nxhxf
Where n is the number of photons, h is plank constant (6,62x10⁻³⁴ J.s), and f is the frequency. Knowing that the power level is 0.120mW (1.2x10⁻⁴ W), the energy in J, for a time of 78 min (4680 s)
E = 1.2x10⁻⁴x4680 = 0.5616 J
The frequency of a photon is its velocity ( c= 3x10⁸ m/s) divided by its wavelength, which is 780 nm = 780x10⁻⁹ m
f = 3x10⁸/780x10⁻⁹
f = 3.846x10¹⁴ s⁻¹
Then, the number of photons is:
0.5616 = nx6,62x10⁻³⁴x3.846x10¹⁴
n = 2.208x10¹⁸ photons.
Earth is the right distance from the sun. It’s protected from harmful solar radiation by its magnetic field and the atmosphere keeps it warm. Earth contains the right chemical ingredients to sustain life such as H2O (water) and C (carbon)
Sugar dissolves and is spread throughout the glass of water<span>. The </span>sand<span> sinks to the bottom. The sugar-</span>water<span> is a homogeneous mixture while the </span>sand-water<span> is a heterogeneous mixture. Both are mixtures, but only the sugar-</span>water<span> can also be called a </span>solution. i got this from :<span>www.chem4kids.com/files/matter_solution.html
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