Answer:
Solar power
Or in some cases, from heat from the sun. ... Solar energy is a renewable free source of energy that is sustainable and totally inexhaustible, unlike fossil fuels that are finite. It is also a non-polluting source of energy and it does not emit any greenhouse gases when producing electricity.
Explanation:
It depends on the substance,but for most substance it is in the gaseous state.
The crystals will not be oxidised since it will be underground
Answer:
Explanation:
An electron in 4s is farther away from nucleus and it has higher energy when compared to electron from 1s.
