1. Frequency: 
The frequency of a light wave is given by:

where
is the speed of light
is the wavelength of the wave
In this problem, we have light with wavelength

Substituting into the equation, we find the frequency:

2. Period: 
The period of a wave is equal to the reciprocal of the frequency:

The frequency of this light wave is
(found in the previous exercise), so the period is:

Answer:
The Nucleus
Explanation:
The nucleus contains the majority of an atom's mass because protons and neutrons are much heavier than electrons, whereas electrons occupy almost all of an atom's volume. I hope this helps you :D
Well I think B hope this helps
Answer:
108 km
Explanation:
The conversion factor between meters and feet is
1 m = 3.28 ft
So the second altitude, written in feet, can be rewritten in meters as

or in kilometers,

the first altitude in kilometers is

so the difference between the two altitudes is

Answer:
Hey there!
Inclined planes are used to lift heavy objects to higher places.
Hope this helps :)