The piece of evidence would suggest an unknown substance is an ionic compound is that it conducts electricity when dissolved in water.
Answer:
The correct answer is option A.
Explanation:
Energy of the photon of an electromagnetic radiation is give by Planck's equation:

Where:
h = Planck's constant
c = speed of light
= Wavelength of the photon's radiation
Energy of photon of 800 nm monochromatic light


Energy per mole of photons:
..[1]
Energy of photon of 400 nm monochromatic light

Energy per mole of photons:
..[2]
[1] ÷ [2]



Answer:
1) Atomic number = number of proton or electrons
Mass number = number of proton or electron + number of neutron