Answer:
The part that completes the nuclear equation is:

Explanation:
<h2>A) Preliminar explanation</h2>
The <em>nuclear equation</em> represents a nuclear reaction: the change of the nucleus of an atom.
The given equation represents an actinium atom releasing an alpha particle.
This is the meaning of each part of the equation:
- Ac is the chemical symbol of actinium
- The superscript to the left of the chemical symbol is the mass number of the atom (number of protons plus number of neutrons). The mass number is 225.
- The subscript to the left of the chemical symbol is the atomic number of the atom (number of protons). The atomic number is 89.
is the symbol of the alpha particle. It is an atom of helium- The mass number is 4
- The atomic number is 2
<h2>B) Solution</h2>
To <em>complete the nuclear equation </em>you must do two balances: mass number balance and atomic number balance.
<u>i) Mass number balance</u>
- 225 = A + 4 ⇒ A = 225 - 4 = 221
<u>ii) Atomic number balance</u>
- 89 = Z + 2 ⇒ Z = 89 - 2 = 87
Therefore, the mass number of the unknown atom is 221, and the atomic number is 87.
From a periodic table, the element with atomic number 87 is francium, Fr.
Now, you have the chemical symbol, the atomic number, and the mass number of the unknown atom, which lets you to write the atom that completes the <em>nuclear equation</em>.

Answer:
A.) the inverse of the square of the distance separating them
Explanation:
Coulombs law states that "the force of attraction between two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them."
Mathematically, F = kq1q2/r²
Where q1 and q2 are the charges
r is the distance between the charges.
According to the law, the force between two charged objects is related to the inverse of the square of the distance separating them.
The force on the proton is 17.4 N.
<h3>What is the force on the proton?</h3>
Now we know that the proton is positively charged and that the force on the charge as it moved through the magnetic field could be given by the relation; F = qvB
Where;
F = force
q = charge
v = velocity
B = magnetic field
Having said this, we can see that;
q = 1.601019 As or C
v = 2.4105 m/s
T = 4.5 T
F = 1.601019 As * 2.4105 m/s * 4.5 T
F = 17.4 N
Learn more about magnetic force:brainly.com/question/12824331
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A driver have to stop for a school bus when the red lights are flashing and there is no barrier between his/her vehicle and the bus.
<h3>What are traffic rules?</h3>
Traffic rules are rules that are expected to follow by the road users for the safety of everyone using the road.
For instance, when the red lights are flashing , it simply means to stop, while the green light means that the vehicle can continue to move, and yellow light means to be at alert to move.
Read more on traffic rules here:
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C. Populations.
Hope that's right.