Oxygen has a total of three isotopes oxygen-16, oxygen-17, and oxygen-18. with their a. m.u. being 15.995, 16.999, and 17.999 respectively. the percent abundance for oxygen-17 is 0.04% and oxygen-18 is 0.2%. find the percent abundance for oxygen-16?

The percentage abundance of oxygen-16 isotope is 99.76 %

Explanation:

We are given:

Three isotopes of oxygen are there, O-16, O-17 and O-18

Mass of Oxygen-16 isotope = 15.995 amu

Mass of Oxygen-17 isotope = 16.999 amu

Mass of Oxygen-18 isotope = 17.999 amu

Percentage abundance of Oxygen-17 isotope = 0.04 %

Percentage abundance of Oxygen-18 isotope = 0.2 %

We know that:

Percentage abundance of all isotopes together is 100 %

So, Percentage abundance of Oxygen-16 isotope = [100 - (0.04 + 0.2)] = 99.76 %

Hence, the percentage abundance of oxygen-16 isotope is 99.76 %

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

po-215 i got it right on the quiz