Remember that like charges repel each other. That is, positive repels positive and negative repels negative. Similar to how the north poles of magnets repel each other and south poles repel. However, at the atomic scale, protons, which have positive charge, are more influenced by the "Strong Force," which binds them close together. If they were to be separated ever so slightly, then the electromagnetic force would take over and they would repel each other like you'd expect.
Neutrons are also held together via the Strong Force, but don't have a charge so when separated, don't have an electromagnetic force pushing them away from each other.
However, electrons act differently. There is no "Strong Force" just the electromagnetic force. So, they keep a great distance from each other.
So in an atom, protons and neutrons stay close to each other, taking up little volume, while electrons take up a lot of volume.
BTW, the reason why electrons and protons act differently when they are close together is because protons are made up of smaller particles the carry this Strong Force. For electrons, there is no smaller constituent. And therefore, all you have is the electromagnetic force to influence it. That's it.
Hope that helps.
Yes it does.
On the periodic table, tin is #50 and Mercury is # 80.
Answer:
49 N
Explanation:
In order to move the box at constant speed, the acceleration of the box must be zero (a=0): this means, according to Newton's second law,
F = ma
that the net force acting on the box, F, must be zero as well.
Here there are two forces acting on the box in the horizontal direction while it is moving:
- The force of push applied by the guy, F
- The frictional force, 
For an object moving on a flat surface, the frictional force is given by

where
is the coefficient of friction
m is the mass of the box
g is the acceleration of gravity
So the equation of the forces becomes

And substituting:

We find the force that must be applied by the guy:

The first thing you should know is that acceleration is a vector, therefore, it has magnitude, and direction.
By definition, we have that the vector acceleration is given by:

Where,
dv/dt: derived from the velocity vector with respect to time,
Therefore, the units of the vector acceleration are:


The symbol of acceleration is:

Answer:
The statements about acceleration that are true are:
a. the si units of acceleration are m/s2.
b. for acceleration, you must have a number, a unit, and a direction.
d. the symbol for acceleration is (True, only if the symbol is the same as above)
Answer:
cause we hear differently
Explanation: