Use the scenario to answer the question. A student has a balloon filled with hydrogen gas. While wearing safety gear, they hold a flame up to the balloon. It explodes with a loud bang and creates a fireball. Is this an endothermic or exothermic reaction, and why?

In a cladogram' when does a group of organisms branch off

Number and variety of living organisms; includes genetic, species, and ecological types.

What evidence for the age of the earth is indicated by the fact that sedimentary rock is found on mountain tops? that the earth has expanded outward from water beds that mountains formed first before anything else that some force lifted the rocks from the water the earth is not very old and has not had time for many rock layers to form