According to Newton's 3rd law of motion, every action has an equal and opposite reaction.
So Wall must apply a force of 50 Newton but in opposite direction.
Hope you got it :-D
The atomic number is the simply the number of protons in the atom. So in the first row with atomic number 2, the number of protons is 2.
If the atom has no charge, which I think you can assume for all of these, the number of electrons is equal to the number of protons. So the number of electrons is also 2.
The number of neutrons (which are the particles with no charge in the nucleus) is simply the mass number minus the atomic number i.e. 4 - 2 = 2.
The isotopic symbol is the symbol which is found on the periodic table of elements. There are 2 numbers associated which each element on the table. The larger is the mass number and the smaller is the atomic number. The atomic number or number of protons is what identifies the element. Looking at the periodic table ( https://sciencenotes.org/wp-content/uploads/2015/01/PeriodicTableOfTheElementsBW.pdf or https://simple.wikipedia.org/wiki/Periodic_table_(big) ), it can be seen that the element on the first row above with an atomic number of 2 is Helium with a symbol He. The number that is included with the name is simply the mass number which is 4 in this case, which tells us that this type of helium has 2 neutrons.
Another type (or isotope) of helium is Helium-3 which has one neutron.
Try the next row and post back if you have trouble with it
Answer:
constant volicty of the pumper when they hit ground 7.03-/s
"<em>The different types of radiation are defined by the the amount of </em><em>energy</em><em> found in the photons. Radio </em><em>waves</em><em> have photons with low energies, microwave photons have a little </em><em>more energy</em><em> than radio </em><em>waves</em><em>, infrared photons have still </em><em>more</em><em>, then visible, ultraviolet, X-rays, and, the </em><em>most</em><em> energetic of all, gamma-rays.</em>"
