The equation relating velocity and wavelength is written below:
v = λf
where λ is the wavelength in m while f is frequency in 1/s.
Let's determine first the frequency from the speed of light:
c = distance/time, where c is the speed of light equal to 3×10⁸ m/s
3×10⁸ m/s = (300 mm)(1 m/1000 mm)/ time
time = 1×10⁻⁹ seconds
Since f = 1/t,
f = 1/1×10⁻⁹ seconds = 10⁹ s⁻¹
Thus,
v = (795×10⁻⁹ m)(10⁹ s⁻¹)
v = 795 m/s
Jasmine have 20 fish because4 times 5 equals 20
Out of the choices given, the one that describes a substance whose atoms all have the same number of protons are an element. The correct answer will be B.
Answer: The mass of 
molecules of phosphorus pentoxide is 20.5 g
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
1 mole of 
weigh = 283.9 g
Thus 0.0772 moles of weigh = 
Thus the mass of molecules of phosphorus pentoxide is 20.5 g
