Answer: 20.4752789138x x 10^23 atoms
To count how many atoms in moles you need to know Avogadro's number. Avogadro's number dictate that for every mole there is 6.022140857 × 10^23 molecule/atoms.
Then 3.4 moles of helium will be 3.4x 6.022140857 x 10^23 atoms= 20.4752789138x x 10^23 atoms
Answer:
phase difference = π / 2
constructive interference
Explanation:
Given data
wavelength = 420 nm
1st beam = 105 nm
path difference = 105 nm
to find out
phase difference and interference pattern of the two beams
solution
we use here equation of phase difference that is
phase difference = 2π / wavelength × Δx
put here value
phase difference = 2π / 420 × 105
phase difference = π / 2
and
we know that here path difference Δx is the integral multiple of the wavelength so it will be constructive interference
Δx is wavelength / 4