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.

the law of original horizontality explains:   why rocks appear in layers. correct answer: b the law suggests that all rock layers are originally laid down (deposited) horizontally and can later be deformed.   the principle is used by geologists to make assumptions about the relative ages of sedimentary rocks.