Answer:
E. just before it reaches the ground.
Explanation:
The "kinetic energy" refers to the energy<em> when an object moves or is in motion.</em> When the ball leaves the racket, it is considered to have a great amount of kinetic energy. However, this decreases as the ball reaches its maximum height, but the potential energy is at its highest. Upon falling down, its kinetic energy increases but its potential energy decreases.
<em>Provided that there's no air resistance,</em><em> the speed of falling is even faster for the ball because of gravity and nothing is slowing it down, </em>which means it will have a<u> maximum kinetic energy</u><u> just before it reaches the ground.</u>
Answer:
A)Protons and electrons
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
when an atom lose or gain the electron ions are formed and number of protons and electrons no longer remain the same.
For example:
An atom of sodium when lose one electron it form positive ion. The number of electrons became 10 and number of protons remain 11.
Na → Na⁺ + 1e⁻
C-13 or Carbon-13 is an isotope of carbon that has a relative abundance of 1.109%. The other isotopes of carbon are C-12 and C-14. We use this percentage to multiply to the total atoms of carbon. The solution is as follows:
2.1×10⁴ atoms * 1.109/100 = 232.89 atoms of C-13
