Why is digestion a necessary process for animals?

Define the kinetic molecular theory

Write the chemical formula for a compound that is made of an element from group 1 and an element from group 17

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)