 In this video, we will be talking about properties of matter. By the end of this video, you should be able to explain what properties of matter are, give examples of physical properties of matter, and give examples of chemical properties of matter. M&M candies and skittles both look very similar. They both come in many colors. They both have sugar in them, and they are about the same size and shape. But they also have differences. Skittles are sour, but M&M's are chocolatey. The weight of a skittle is greater than the weight of an M&M. The outer shell of a skittle melts faster than the outer shell of an M&M. These similarities and differences are properties of matter. Properties of matter are characteristics of matter that can be observed or measured. There are two main types of properties, physical properties and chemical properties. Physical properties can be observed without changing the identity and composition of a substance. Examples are color, odor, melting point, boiling point, hardness, the ability to conduct electricity, length, shape, mass, weight, luster, which means shininess, malleability, which means the ability to be pounded into shapes, ductility, which means the ability to be drawn into a wire, viscosity, which means thickness or stickiness, magnetism and the ability to be attracted to a magnet, and many others. The states of matter are also an example of physical properties. Chemical properties are the other type of property. They are characteristics of a substance that can be observed only by performing chemical reactions. This means you can't observe chemical properties by just touching or viewing a sample. The identity of the sample must be changed in order to observe the property. We will learn more about what chemical reactions are in a future lesson. One example of a chemical property is combustibility or being combustible. This is the ability of a substance to light on fire. You may have noticed that if you burn wood in your fireplace, over time that wood will change from its original wood shape to something black and charred and easy to break up with a stick. The wood is changing into something else and a chemical reaction is occurring. Therefore, combustibility is a chemical property. Flammability is similar to combustibility in that it's the ability of a substance to light on fire. However, flammable materials are combustible materials that light on fire very easily, like the gas in a gas stove or alcohols or gasoline. Because these involve a chemical reaction, flammability is also a chemical property. You can't see flammability without actually lighting something on fire. Another example of a chemical property is reactivity with other chemicals. That is the ability to have a chemical reaction. Sometimes when you mix two things together, you get a big change and it turns into something else. Toxicity, which is the quality of being toxic or poisonous, is also a chemical property because it involves chemical reactions. And that's why toxic substances, poisonous substances, can be very harmful. It's through the chemical reactions that they produce. Another chemical property is the ability to rust. Iron rust, for example, and that's a chemical reaction. And the ability of silver to tarnish and get all that black stuff on it that you have to use silver polish to get off. Tarnishing is also a chemical reaction. So the ability to tarnish is a chemical property. Acid rain is also a chemical property. You may have noticed some statues that have little pit marks or look like they've been eroded over time. Often that's due to acid in the rain. And being acidic is a chemical property because it involves a chemical reaction. In summary, properties of matter are characteristics that can be observed or measured. And there are two main types of properties, physical properties and chemical properties.