Answer:

Explanation:
Given that,
The speed of an electromagnetic wave traveling in a transparent nonmagnetic substance is given by :

Where
k is the dielectric constant of the substance.
v is the speed of light in water


So, the speed of light in water is 
Answer:
UV light is more powerful as it has greater energy.
Explanation:
The energy propagated by electromagnetic waves ( light ) through vacuum or medium is known as electromagnetic radiation.
The frequency/wavelength range of electromagnetic radiation is known as electromagnetic spectrum. The electromagnetic spectrum ranging from gamma ray to radio waves.
Frequency range of UV light = ( 8 x 10¹⁴ to 3 x 10¹⁶ ) Hz
Frequency range of Microwaves = ( 300 x 10⁶ to 300 x 10⁹ ) Hz
Ratio of UV light to Microwaves = (
to
)
= ( 2.66 x 10⁶ to 1 x 10⁸ )
Energy of electromagnetic radiation is given by the relation:
E = hν
Here h is plank's constant and ν is frequency.
UV light is more powerful than Microwaves as frequency of UV light is greater than frequency of microwaves. Thus, by the above equation, the energy of UV light is more than energy of Microwaves.
The mineral with Mohs hardness would be scratched because the mineral with Mohs 7 hardness is stronger than the Mohs 5 mineral. Eventually, that mineral would turn into dust if you kept rubbing it.
Answer:
A.c
Explanation:
The chromosphere is above the photosphere, the visible "surface" of the Sun. It lies below the solar corona, the Sun's upper atmosphere, which extends many thousands of kilometers above the chromosphere into space. The plasma (electrically charged gas) in the chromosphere has a very low density.
In basic terms it is the 2nd one out from the core.
<h2>Answer: free electrons</h2>
<u>Plasma</u> is known as the 4th state of matter and is itself ionized gas. In this sense, ionization consists of the production of ions, which are <u>electrically charged atoms or molecules due to</u><u> the excess or lack of electrons</u><u> with respect to a neutral atom or molecule.
</u>
That is why in this process there are always<u> free electrons</u>. Therefore in heating gas to create plasma can yield free electrons, and the correct option is D.