I think calcium but i could be wrong
Answer:
hormones
Explanation:
An example of materials commonly released this way is hormones. These are chemical messengers that are sent to the pituitary gland where they are released directly into the bloodstream. The blood then carries the hormones to different organs and tissues of the body in order to exert their specific function which varies depending on the specific type of hormones being secreted.
This might help:
https://quizlet.com/1965478/environmental-health-test-1-flash-cards/
It is a force resulting from the redistribution of energy contained by electrons, which tends to bind atoms together to form different types of molecules
