Answer:
Option (B) is correct.
Explanation:
Given that the molecules of hydrogen gas (
) react with molecules of oxygen gas (
) in a sealed reaction chamber to produce water (
).
The governing equation for the reaction is

From the given, the only fact that can be observed that 2 moles of
and 1 mole of
reacts to produce 2 moles of
.
As the mass of 1 mole of
grams ... (i)
The mass of 1 mole of
grams ...(ii)
The mass of 1 mole of
grams (iii)
Now, the mass of the reactant = Mass of 2 moles of
+ mass 1 mole of 
[ using equations (i) and (ii)]
grams.
Mass of the product = Mass of 2 moles of 
[ using equations (iii)]
=36 grams
As the mass of reactants = mass of the product.
So, mass is conserved.
Hence, option (B) is correct.
The intensity on a screen 20 ft from the light will be 0.125-foot candles.
<h3>What is the distance?</h3>
Distance is a numerical representation of the length between two objects or locations.
The intensity I of light varies inversely as the square of the distance D from the source;
I∝(1/D²)
The ratio of the intensity of the two cases;

Hence, the intensity on a screen 20 ft from the light will be 0.125 foot-candles
To learn more about the distance refer to the link;
brainly.com/question/26711747
#SPJ1
It probably is the actual answer.
The answer to this is aluminum foil.