Synergistic Interaction
Hormones
Burning is a chemical change, and as such, produces new forms of matter that were not there before. These new substances are called products, and in the case of burning, or combustion, they are often water vapor and carbon dioxide.
A change that produces a new substance is called a chemical reaction. The substance initially involved in a chemical reaction are called reactants or reagents.
The earth is made of chemicals. These are called natural chemicals. When man makes chemicals that are not natural chemicals and releases these into the environment this upsets the balance of nature and things die.
controlled products
hormones
Hormones
A change in the DNA sequence caused by a mistake in DNA replication or exposure to radiation or chemicals is called mutation.
critical period
These are called lesions. Brain lesions can be caused by injury, infection, exposure to certain chemicals, problems with the immune system, and more. Typically, their cause is unknown.These are called lesions. Brain lesions can be caused by injury, infection, exposure to certain chemicals, problems with the immune system, and more. Typically, their cause is unknown.
There is considerable interest these days in benevolent chemicals called "free radical scavengers."