An example of an external stimulus is a decrease in oxygen levels in the blood during exercise.
Option C
<h3>What is stimulus?</h3>
A stimulus is defined as a thing or sensation that causes a specific reaction in an organ or tissue of a living organism
There are two types of stimuli:
- Internal stimulus
- External stimulus
Learn more about stimulus:
brainly.com/question/20117556
C.Pennsylvania Titusville is in the state of Pennsylvania
Answer:
false?
Explanation:
The octet rule refers to the tendency of atoms to prefer to have eight electrons in the valence shell. When atoms have fewer than eight electrons, they tend to react and form more stable compounds
The answer is B Covalent bonds