From Literature:
The amount of energy in the photons is given by this equation:
E = hf
where E = energy
h = Planck's constant = 6.63 * 10^-34 Joule seconds
f = frequency of the light, Hz
Given:
E= 3.00 eV and Planck's constant
To solve for the frequency, E = 3.00 eV
1 electronvolt = 1.60218 x 10^-19 Joules
3 * 1.60218 x 10^-19 Joules = 6.63 * 10^-34 Joule seconds * f
f = 7.25 x 10^14 /second or hertz
Therefore, the threshold frequency of the material is 7.25 x 10^14 Hertz.
Answer:
B. 14
Explanation:
For an element:
- Atomic number: is the number of protons in the nucleus (p)
- Mass number: it is the number of protons (p) + neutrons (n) in the nucleus
For Al (aluminium), we have:
p = 13
p + n = 27
Substituting the first equation into the second one, we find the number of neutrons:
n = 27 - p = 27 - 13 = 14
Answer:
Free fall and air resistance
The formula is G=mass(1)x mass(2)
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6.67x10x-11
note that 10x-11 is in standard form but i could not write it. It is 10 raised to power negative 11
Answer:
90%
Explanation:
if you lose 10% of a 100 you get 90
