Answer:
Magnetic fields and Electric fields
Explanation:
Answer:
DNA
Explanation: Because if you stretch DNA it gets longer.
Answer;
The above statement is true
upon heating a copper sample will expand, leading to a lower density
Explanation;
-The density of solids decreased with increase in temperature and vice versa. The increase in temperature causes the volume of the solid to increase which as a result decreases the density as Density=Mass/Volume. The temperature of a body is the average kinetic energy of the molecules present in it.
In other words; The temperature of a body is the average kinetic energy of the molecules present in it. Therefore; when heat is supplied ( or temperature is increased) the average kinetic energy increases which increases the volume and thus density decreases.
Explanation:
It is known that charge on xenon nucleus is 
equal to +54e. And, charge on the proton is 
equal to +e. So, radius of the nucleus is as follows.
r = 
= 3.0 fm
Let us assume that nucleus is a point charge. Hence, the distance between proton and nucleus will be as follows.
d = r + 2.5
= (3.0 + 2.5) fm
= 5.5 fm
= 
(as 1 fm = 
)
Therefore, electrostatic repulsive force on proton is calculated as follows.
F = 
Putting the given values into the above formula as follows.
F =
= 
= 
= 411.2 N
or, = 
N
Thus, we ca conclude that N is the electric force on a proton 2.5 fm from the surface of the nucleus.
Answer: The sample that contains the greater number of molecules is water.
Explanation: To calculate the number of molecules, it is used the Avogadro's number ( 
particles/molecules). So, considering that the mass to water and carbon dioxide is 1g (it can be any other number), the relationship between moles and molar weight is:
To water: 
= 0.05 moles.
Therefore,
1 mol ---- molecules
0.05 moles ---- x
x = 
molecules of water.
To carbon dioxide: 
= 0.02 moles.
Therefore,
1 mol ---- molecules
0.02 moles ---- y
y = 
molecules of carbon dioxide.
