Answer:
It is better to compare the average height gain of control and experimental groups of plants to eliminate all other variables.
Explanation:
If you evaluate individual plants, the data may vary. The experimental group is the one where an experimental procedure is performed while the control group does not receive any treatment.
Gravitational Energy
Possibly
Key Concept about star formation
Once you form a star, it's formed. To undo it, it's hard.
A cloud of interstellar gas can contract due to its own gravity.
When the gas cloud contracts, gravitational potential energy = converted into heat energy.
Hope this helps!
