Which statement best describes why a chemical change is different from a physical change?
a) a chemical change results in a different state of matter, and a physical change results in a new substance being formed.
b) a chemical change is used to identify characteristics of a substance, and a physical change identifies the behavior of a substance when in a reaction.
c)a chemical change is used by scientists to create new substances, and a physical change happens naturally.
d) a chemical change results in a new substance being formed; whereas, a physical change will result in a different state of matter.

d) A chemical change results in a new substance being formed; whereas, a physical change will result in a different state of matter.

Explanation:

A chemical change results in a different state of matter, and a physical change results in a new substance being formed.

Explanation:

Chemical change:

Chemical changes occur when the bonds are formed or broken between atoms or molecules. This results in formation of completely different state of matter having different properties. They are irreversible.

Example of chemical change : burning of wood

When wood is burnt, ash is formed and produces energy in the form of light and heat. This ash cannot be converted back into wood.

Physical change:

But physical changes doesn't lead to formation of new substance rather they lead to the change in the shape or state of the object. They can be either reversible or irreversible.

Example of physics change : chopping of wood

When  the wood is chopped its properties remains same. Only the shape and the structure of the wood will be altered.

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.