Distance = 556 km
Time = 3.4 h
Speed = Distance / Time = 556 / 3.4 = 163.52 km/h
Hello there!
To determine the fraction of the hydrogen atom's mass that is in the nucleus, we have to keep in mind that
a Hydrogen atom has 1 proton and 1 electron.
Protons are in the nucleus while electrons are in electron shells surrounding the nucleus.
The mass of the nucleus will be equal to the mass of 1 proton and we can express the fraction as follows:

So, the fraction of the hydrogen atom's mass that is in the nucleus is
0,9995. That means that almost all the mass of this atom is at the nucleus.
Have a nice day!
Answer:
1. Many different hypotheses will be tested.
Explanation:
Scientists test every hypothesis they make for their investigation, before moving onto bigger conclusions.