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: 72200
Explanation:
First you must find the height for this is on an inclined hill using:
h=Lsin(angle) —> 28.0sin(11.0) = 5.34
Now you would just use the PE equation (mgh) because you are finding ME and when you starting from the top KE=0, showing that what ever answer you get from PE would equal the same for ME.
Using mgh:
m=1380
g=9.80
h=5.34
(1380)(9.8)(5.34)
=72218.16
*Rounding to the 3rd=72200
Hope this helps :)
Answer:
The mother has to sit 2.17 ft from the center on the other side of the seesaw.
Explanation:
We are trying to find the sum of torques given by the weights of mother and daughter to be zero.
If the torque of the daughter on one side of the pivoting point is given by:
5.5 ft x 63.5 lb x g = 349.25 g ft lb
we need that the absolute value of the torque exerted by the mom (160.9 lb) to be the same in magnitude (and of course opposite direction). So we assume that "d" is the distance at which the mother locates to make this torque equal in magnitude to her daughter's torque:
d x 160.9 lb x g = 349.25 g ft lb
d = 2.17 ft
Answer: electric field
Explanation: when a charge is placed in space, it alters the space around it by creating an electric field.
This electric field has the ability to exert a force (f) on any test charge(q) placed within this vicinity.
This is the reason why a charge can either attract or repel another charge.
The first opiton is the answer A)<span>Rahul’s weight
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