Answer:Atomic model keep changing because the electrons around the nucleus are not fixed and they keeps rotating or changing their position in valence orbits around the nucleus.
Explanation:
Answer:

Explanation:
As we know that there is no external torque on the system of two disc
then the angular momentum of the system will remains conserved
So we will have

now we have

also we have

now from above equation we have

now we have


Answer:
<em>About four million tons of </em><em><u>matter</u></em><em> are converted to energy in the Sun’s core every second</em>
Explanation:
<u>The Sun
</u>
It's estimated that The Sun fuses near 600 million tons
of hydrogen into helium every second. As a result, 4 million tons of matter are converted to energy every second according to Einstein's equation 
Answer:
C
Explanation:
Fusion and fission are similar in that they both release large amounts of energy. Nuclear fusion is a process in which two nuclei join to form a larger nucleus. Nuclear fission is a process in which a nucleus splits into two smaller nuclei.