Answer:

Explanation:
The refractive index of a medium is a measure to know how much the speed of light within the medium is reduced. It can be calculated with the next equation:
(1)
Where:


The speed of light in the vacuum is approximately 300,000 km/s. In order to work with the same units let's do the proper conversion with the velocity of the medium:

Finally, replacing the data in (1):

Out of the choices given, the statement about how light travels is "<span>Light can travel in a vacuum, and it travels faster if the light source is moving."</span>
<span>1. 10x
2. fault line
3. UV Waves
4. through solids and liquids
5. inner core
6. low temperature
7. cinder cone
8. earth's core
9. they are all caused by plate movement
10. inner mantle
11. transverse
12.divergent
13. none of these
14. fault
15. Lithospheric plates
16. foreshocks and aftershocks can happen at the same time
17. stratosphere
18. this question is not complete</span>
Celina should perform the following method to get pure water:
Boil the water in a pan, as the water boils it changes into gas (water vapours) these vapours should be cooled down through the process of condensation which changes gas into liquid form, Through this process germs would be killed due to high temperature and the salt will remain in the pan as salt has higher boiling point than water,
Water equal to iron is greater than cooper