Atoms are made up of three subatomic particles called protons, neutrons, and electrons.
Protons and neutrons are located in the nucleus.
All protons have a positive charge.
All neutrons have no charge or are neutral.
Electrons orbit around the nucleus and have a negative charge.
Kinetic
because the boy is walking in the street soo it has force to use

Actually Welcome to the Concept of the Lens and Ray Optics.
We must understand the Concept that,
1.) When a beam of parallel light pass through a Convex lens, all the rays get deviated and converges to a special point at the axis that is a Focus.
2.) When a beam of light passes through the Concave lens,the light beams diverge from one another forming a virtual focus in the primary side of lens,
Hence the above given diagram beam rays are diverging, it is a CONCAVE LENS
answer is C.) Concave lens
Answer: option D is right.
Explanation: There are four types of fundamental forces in nature.These are named as gravitational force,electromagnetic force,strong nuclear force and weak nuclear force.
As per the question we have to understand the role of strong nuclear force and weak nuclear force.
An atom consists of a nucleus surrounded by extra nuclear part consisting of electrons in various orbits.The nucleus contains two basic particles called protons and neutrons .Protons are positively charged while neutrons are neutral.Protons being positively charged will impart repulsive force on each other and may come out of the nucleus.But the nucleus is stable.That is due to the strong nuclear force.
Strong nuclear force is a spin dependent and charge independent force which comes into existence due to the mutual interaction of gluons which binds the protons and neutrons .Hence it is attractive in nature.It's 100 times more stronger than electromagnetic force also.
Weak nuclear force comes into existence during radio -active decay .This force is due to the exchange of ' w' and 'z' bosons[the particles like protons and neutrons having integral or zero spin] which are heavier in nature.The role of it is to change protons into neutrons and vice versa.Its a short range force.
Hence the option D is right.
The answer is chemical weathering