Protons and neutrons are packed together in a very small region called nucleus. Protons are positively charged and we know that like charges repel. Then how is it that protons are not repelling each other and flying away from nucleus?
You may think that gravitational force is holding all the protons together but it is not so. Gravitational force is many times weaker than repulsive force.
It is actually strong force which holds proton together. At this short distance, strong force comes into play and is several times stronger than the repulsive force.
Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.
We use the Planck’s formula:
E = hv
where,
E = energy, h = planck’s constant = 6.6x10^-34 J s, v =
frequency in Hz (Hz = 1 / s)
Subsituting the values to find for E:
E = (6.6×10^-34 J s) * 9.85×10^14 / s
E = 6.5x10^-19 J