The correct answer is D.
A nucleon<span> is one of either of the two types of subatomic particles (neutrons and protons) which are located in the nucleus of atoms.
</span>
The total number of nucleon in the nucleus of an atom gives you an idea about the mass of that atom. In fact, one may refer mass number as nucleon number.
Simply put, nucleons are the particles that make nucleus of an atom and are held up together inside the nucleus due to nuclear force.
 
        
        
        
On behalf of the state, write an invitation for the siblings for the gala dinner 
Hello there, we would like to welcome you to the gala dinner hope you can come :)
 
        
             
        
        
        
<h3>Hello There!!</h3>
<h3><u>Given</u>,</h3>
Force(F) = 150N
Mass(m) = 90kg
<h3><u>To </u><u>Find,</u></h3>
Acceleration(a) = ?
<h3><u>We know,</u></h3>
F= m×a


<h3>Hope this helps</h3>
 
        
        
        
This question is incomplete, the complete question is;
Two plane mirrors intersect at right angles. A laser beam strikes the first of them at a point 11.5 cm from their point of intersection, as shown in the figure.
For what angle of incidence at the first mirror will this ray strike the midpoint of the second mirror (which is 28.0 cmcm long) after reflecting from the first mirror
Answer: angle of incidence is 39.4°
Explanation:
Given that;
two plain mirrors intersect at right angle (90°)
distance d = 11.5 cm
S = 28.0 cm
Now the angle that the reflection ray males with first the mirror equal theta  (∅)
so
tan∅ = (S/2) / d
tan∅ = (28/2) / 11.5
tan∅ = 14 / 11.5 
tan∅ = 1.2173
∅ = tan⁻¹ (1.2173)
∅ = 50.6°
so angle of incidence = 90° - ∅
= 90° - 50.6°
= 39.4°
Therefore angle of incidence is 39.4°