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.
It is caco3 ok thats the answer
Answer:
A options hydrogen
Explanation:
valence outermost element is hydrogen.
Answer:Rocket is lauched for first one, Second one is the wagon one and third one is seabelt impact.
Explanation:
Answer:
Explanation:
Cr₂O₃ ( chromium oxide )
Mass of Cr₂O₃⁻ = 2 x 52 + 3 x 16 = 104 + 48 = 152
152 gram chromium oxide contains 104 grams chromium
152 tonnes chromium oxide contains 104 tonnes chromium
5 tonnes chromium oxide contains 104 x 5 / 152 tonnes chromium
mass of chromium required = 104 x 5 / 152 tonnes
= 3.42 tonnes .