Question

What is common between Marble and egg shells? How can you test this common feature?

Answer 1

They are both made up of calcium carbonate
We can test this common feature by adding HCl to it

Answer 2

Marble and egg shells have calcium carbonate.

Explanation:

The carbonic salt of calcium is calcium carbonate and the molecular formula is $CaCO_{3}$.

$CaCO_{3}$ is clinically used as phosphate buffer which is mainly used in hemodialysis. And also used as an antacid for instant relief for acidity.

For treating of osteoporosis disease $CaCO_{3}$ is used as calcium supplement. Calcium carbonate is naturally occurs in rocks an main component of shell of marine organisms and eggs. And occurs as minerals like aragonite calcite. Artificially occurs mainly in marbles.

Therefore, most common factor present in Marble and egg shells is calcium carbonate.