To find the Percent Composition of an atom, you use this formula:
Mass of element in the compound you're studying on ( in this case it's 5 since there is 5 Hydrogens) over the mass of the compound (which is here 79), Multiplied by 100 since you want a percent.
So we get:

So you get about:


So, the percent composition of Hydrogen in NH4HCO3 is 6.3%
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Answer: a,b
Explanation: because a scientific theory is something that been thought of and tested multiple times.
Answer:
B. accepted value x 0.1
Explanation:
in the equation provided

Maximum allowed value of percentage error = 10%
put this value in the equation in stead of percentage error we get,

so maximum error = .1 x accepted value
10 % percentage error means the experimental value has 10 % error compared to accepted value.so error will be 10 % of the accepted value
or .1 times of accepted value