The correct answer is B because isotopes have different numbers of neutrons, and neutrons are located in the nucleus
Hope this helps
Answer:
Mass of the steel cube = 7800 kg
Volume of the steel = 1.025 cubic centimetre
Explanation:
Given:
The density of the steel = 7.8
Side of the cube = 12 cm
<u>(1)The mass of steel cube :</u>
We know that,

We are given with density and sides of the cube
then volume of the cube
=
= 
= 1000 cubic centimetre
Now


mass = 7800 kg
<u>(2)volume of steel:</u>
Given the mass = 8 kg

Substituting the values


volume = 1.025 cubic centimetre
Answer
Nature of the surfaces.
Explanation
Friction is the the force that opposes motion between two surfaces that are in relative motion. If two objects are in contact, one of it or both must be in motion for friction to exist.
Friction is affected by a number of factors.
One is the weight of the object. The more the weight of the object the higher the friction between it and the surface.
The other factor is the nature of the surfaces. Rough surfaces contribute to high friction while smooth surfaces reduces the friction between surfaces.