How to find percentage abundanace

Answer and Explanation:

How to Calculate the Percent Abundance of an Isotope

Step 1: Find the Average Atomic Mass. Identify the atomic mass of the element from your isotopic abundance problem on the periodic table. ...

Step 2: Set Up the Relative Abundance Problem. ...

Step 3: Solve for x to Get the Relative Abundance of the Unknown Isotope. ...        

 Step 4: Find percent abundance.

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

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

b. examine and describe cells