Answer:
The percent abundance of oxygen-18 is 1.9066%.
Explanation:
The average atomic mass of oxygen is given by:

Where:
m: is the atomic mass
%: is the percent abundance
Since the sum of the percent abundance of oxygen isotopes must be equal to 1, we have:



Hence, the percent abundance of O-18 is:

Hence, the percent abundance of oxygen-18 is:
Therefore, the percent abundance of oxygen-18 is 1.9066%.
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Answer:
= 62.1 hours
Explanation:
Energy provide by the serving is 65 cal
= 65 cal × 4.184 Kj = 271.96 kJ
271.96 KJ = 271960 J
Energy required for 1minute of energy
= 73 x 1
= 73 J/min
So, 271960 joules will be required for 271960 heart beat
Minutes = 271960 / 73
= 3593.94 minutes
Time in hours = 3725.429 / 60
= 62.1 hours
An atomic mass unit is defined as precisely 1/12 the mass of an atom of carbon-12.