Answer:
B. A repulsive force of 8.0*10^3 N.
Explanation:
As we know by Coulomb's law that the electrostatic force between two charges is given as

here we know that


r = 3.0 m
now we have


since both charges are similar charges so they will repel each other by the force we calculated above so correct answer will be
B. A repulsive force of 8.0*10^3 N.
Answer:Radioactive
Explanation:
The radioactive nucleus is the one which does not has enough binding energy to hold the nucleus in a stable state and thus radiates either electron or proton to become a stable element.
A radioactive element is formed when after billions of years such as uranium and thorium. The stability of the nucleus depends upon the opposition of attractive and repulsive force among the nucleus.
Answer:
Those substances which can conduct electricity are called conductors, while those substances which don't conduct electricity are called insulators.
Resistance is the obstruction provided by the material through which the current passes,so since conductors conduct electricity and insulators don't,so the obstruction i.e resistance provided by the conductor must be less,while insulators being unable to conduct electricity,has very high resistance.
Example of conductor is copper
Example of insulator is plastic
Matter occupies space and has mass