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.
Answer: 0.83mol/m3
Explanation:
Number of mole = 2.5 mmol = 0.0025mol
Recall
1L = 0.001m3
Therefore 3L = 3x0.001 = 0.003m3
0.003m3 contains 0.0025mol
Therefore, 1m3 will contain = 0.0025/0.003 = 0.83mol
The concentration in mol/m3 is 0.83mol/m3
.36 g of caffeine for this problem. 2% of 18g is 0.36g
Answer:
false
Explanation:
The particles are held together too strongly to allow movement from place to place but the particles do vibrate about their position in the structure. With an increase in temperature, the particles gain kinetic energy and vibrate faster and more strongly
