Explanation:
Tests for gases
Hydrogen, oxygen, carbon dioxide, ammonia and chlorine can be identified using different tests.
Hydrogen. A lighted wooden splint makes a popping sound in a test tube of hydrogen.
Oxygen. A glowing wooden splint relights in a test tube of oxygen.
An insertion mutation occured.
After the mutation, a letter was inserted, and the others remained intact. The number of letters increased by 1.
