The circumstances when scientists use observational research and opinion based research is when they include animals or things that cannot control for a product. Observational research is a type of research which only observes ongoing behavior and studies about it and the results only rely on the behavior observed.
<h2>Heat energy is the result of the movement of tiny particles called atoms, molecules or ions in solids, liquids and gases. Heat energy can be transferred from one object to another. </h2>
<h2>Thermal energy is produced when a rise in temperature causes atoms and molecules to move faster and collide with each other. The energy that comes from the temperature of the heated substance is called thermal energy.</h2>
<h2>MARK ME AS BRAINLIST!</h2>
Answer: C the study of living things
Explanation:
The endocrine system is made of a series of glands that release chemicals directly into the bloodstream.
Answer: I Personally plan to Participate in study groups, And get help when I need it.
(If you could make me Brainliest i would be happy)