Answer: Bubbles, burning, odor, color change, and rusting.
Explanation: Chemical changes are changes to something that is irreversible.
The correct answer would be the first option. Material A having a smaller latent heat of fusion would mean that it will take only less energy to phase change into the liquid phase. Latent of heat of fusion is the amount of energy needed of a substance to phase change from solid to liquid or liquid to solid.
Answer : The energy released by an electron in a mercury atom to produce a photon of this light must be, 
Explanation : Given,
Wavelength = 
conversion used : 
Formula used :
As, 
So, 
where,
= frequency
h = Planck's constant = 
= wavelength = 
c = speed of light = 
Now put all the given values in the above formula, we get:
Therefore, the energy released by an electron in a mercury atom to produce a photon of this light must be,
The answer is: [D]: a reactant.
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<span>2 Na + CaF</span>₂<span> = 2 NaF + Ca
is an example of a </span>single- replacement
answer D
hope this helps!
