Answer:
Meter (m)
Explanation:
The wavelenght of a light wave is a measure of the distance between two successive crests (or two successive troughs) of a light wave.
Since the SI units for the distance is the meter (m), then the SI unit for the wavelength is also the meter (m).
Wavelength is related to the frequency of the light wave by:
where
c is the speed of light
f is the frequency of the light
Molecular formulas:
The empirical formula of a compound tells only the ratio between atoms of each element. The empirical formula CH₂O indicates that in this compound,
The molecular weight (molar mass) of the molecule depends on how many such sets of atoms in each molecule. The empirical formula doesn't tell anything about that number.
It's possible to <em>add</em> more of those sets of atoms to a molecular formula to increase its molar mass. For every extra set of those atoms added, the molar mass increase by the mass of that set of atoms. The mass of one mole of C atoms, two mole of H atoms, and one mole of O atoms is .
It takes one set of those atoms to achieve a molar mass of 30.0 g/mol. Hence the molecular formula CH₂O.
It takes two sets of those atoms to achieve a molar mass of 60.0 g/mol. Hence the molecular formula C₂H₄O₂.
It takes sets of those atoms to achieve a molar mass of 180.0 g/mol. Hence the molecular formula C₆H₁₂O₆.
Answer:
de Broglie wavelength of an electron with speed 0.78 c taking relativistic effects into account is given as:
λ = 1.943 * 10^(-12) m
Explanation:
Given:
v = 0.78 c
we know:
c = speed of light = 3 * 10^8 m/s
mass of electron = m = 9.1 × 10-31 kg
de Broglie wavelength:
In 1924 a French physicist Louis de Broglie assumed that for particles the same relations are valid as for the photon:
(Dual-nature of a particle)
Let the wavelength be = λ
According to de Broglie:
λ = h/p = h/mv
where h is planck's constant = 6.626176 x 10^-34 Js
and p is momentum.
Taking relativistic effects into account, we know that the momentum of the particle changes by a factor 'γ'.
At low speed, γ is almost 1. However, at very high velocity (comparable to light), it has a great effect on momentum.
γ =
γ = 1.6
Now at 0.78 c, considering relativistic effects, we know:
λ = h/γp = h/γ*mv
= (6.62 x 10^(-34))/(1.6*0.78*3*10^(8)*9.1 × 10-31
λ = 1.943 * 10^(-12) m