What is chemistry?
To put it simply, chemistry is the study of matter and its properties. Chemistry is a science; people who study chemistry are called chemists.
What is a "property of matter"?
When chemists study matter, they use the scientific method to observe the properties of matter. Two important properties of matter are physical and chemical. To figure out the physical properties of matter, you cannot change the substance. You can figure out physical properties by using the three of the four senses (taste, touch, and sight). Let's look at that milk and figure out its physical properties. It is white, liquid, you can't see through it, smells creamy, feels slippery like water.
Another important property of matter is a chemical property. To figure out chemical properties of matter you have to change the substance. To find out the chemical properties of matter you have to mix a substance with different things like chemicals, fire, and oxygen. Do not perform any chemistry experiments without adult supervision! An example of a chemical reaction would be a rusty bike. When oxygen combines with iron, rust is formed. This taught us that one chemical property of iron is that it changes when exposed to oxygen.
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