Answer:
4. Electrons move from higher energy states to lower energy states.
Explanation:
When electrons fall from a higher (excited) energy state to a lower energy state, it loses/gives out energy.
This energy is given out by the emission of photons (quanta of light) by the electron.
Answer:
A. nuclear fusion reactions
C. it's still hot from the big bang
Explanation:
The inside of the earth is hot due to some reasons. This heat provides the internal energy the drives processes within the earth interior. Here are some of the ways in which the heat has accumulated:
- Nuclear reactions within the earth interior by fusion and other radioactive processes releases a large amount of heat.
- Some heat accreted during the early formation of the earth and has not been lost till this day.
- Heating due to friction
These are some of the sources of the earth's internal heat.
Velocity is displacement/time
(Displacement is the overall change in distance)
So you’ll want to divide 200 by 25, which should give you:
8 m/s
Answer:

Explanation:
Given data
Electric potential at point a is Ua=5.4×10⁻⁸J
q₂ moves to point b where a negative work done on it
Required
Electric potential energy Ub
Solution
When a particle moves from a point where the potential is Ua to a point where it is Ub the change in potential energy is equal to work done where the force exerted on the charge is conservative and work done is given by:

Now substitute the given values
So
