Answer:
E. None of these
Explanation:
We know, By GAS laws,
PV = NRT, where p- pressure, v- volume, n- number of moles, R- gas constant ,and T- temperature
Now, In the question, the number of moles remains the same as the gas is the same. so n is constant so we can compare n before and after a temperature change.
= 
where P1= 1 atm, P2 = 10 atm, V1= 20 mL, T1= 10°C and T2= 100°C
We don't have to worry about the standard units as they are present equally on both the sides and get cut, same goes for R( gas constant)
So putting values, we get

Cutting, R on both sides and moving contents to the right so that only V2 is left on the left.

∴ V2 = 
∴ V2 = 20mL
Single replacement because only one letter is being switched out in the reaction
Most likely the equation yields a new compound XY. This is a synthesis reaction. <span>Synthesis
reaction is a reaction where two or more substances combine to form a new
compound. It is a reaction which releases energy in the form of heat and
light. Therefore, it is an exothermic reaction.</span>
Is there a picture of the isotope or?- becaue I can’t help if I don’t have a visual.
Phenolphthalein<span> is often used as an indicator in acid–base titrations. For this application, it </span>turns<span> colorless in acidic solutions and </span>pink<span> in basic solutions. </span>Phenolphthalein<span> is slightly soluble in water and usually is dissolved in alcohols for use in experiments.
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