1. Mixtures and Pure Substances REVIEW

2. Mixtures Scientists often classify matter by sorting it into groups. This is not easy. Normally, matter is all mixed up! That is, matter is usually found in mixtures. A mixture is a combination of different kinds of matter, in which the different kinds are not changed by being put together. The parts of a mixture can be separated. They can be separated by using the properties of the substances.mixture For example, if you mix jellybeans and pebbles together, the pebbles stay pebbles and the jellybeans stay jellybeans. If you were patient, you could pick out the jellybeans one by one and eat them (without breaking your teeth). You probably used the property of color to find the parts of the mixture. But a jellybean is a mixture too, a mixture of coloring, sugar, and flavoring. Could you pick out the parts of a jellybean just using your fingers? Probably not. Some mixtures are harder to sort out than others, like jellybeans or salt water. Chemists are very good at figuring out ways to separate mixtures, because they know the properties of many different kinds of matter. Click to continue…

3. Substances The parts of a mixture are called substances. A substance (SUB-stans) is made of only one kind of matter. Each substance has its own properties which do not change. This is how chemists can tell one substance apart from another, and why knowing the properties of matter is important. A chemist is a kind of detective in some ways.substance There are different ways of sorting substances into groups. You could group them by color, or by hardness, or by whether they are poisonous. You could group them by state: solid, liquid, or gas. However, whatever groups you choose, they should be useful groups that help you understand what you are studying. Click to continue…

4. Elements and Compounds Most substances on Earth are in the form of compounds. A compound (COM- pownd) is a substance which has its own properties but which can be broken down into other substances. Chemists break down compounds using special chemical methods which may include heat, electricity, and adding other substances to the compounds.compound Even in the time of the alchemists, people knew that there were some kinds of substances which were special because they could not be broken down. These substances, called elements (ELL-uh-mentz), were the basic building blocks of all matter. All other matter could be broken down into elements, but elements could not be broken into anything else. These substances, such as silver, lead, mercury, tin, copper, gold, and iron, were known to the alchemists. Gradually, more elements were discovered, and today there are 110 known elements.elements Click to continue…

5. http://www.dmturner.org/Teacher/Library/5thText/ChemPart2.htm Scientists classify matter in order to study it. Matter usually occurs in mixtures, which can be separated. The parts of a mixture are substances. Each substance has its own properties. Most substances are compounds, and can be broken into other substances using chemical means. Some substances are called elements, and they cannot be broken down into other substances.

6. Mixtures Computer Assignment Click on the link below and use the website to complete questions 1-3. http://www.harcourtschool.com/activity/mixture/mixture.ht mlhttp://www.harcourtschool.com/activity/mixture/mixture.ht ml Use what you know along with page 18 in the brown chemistry book, the website below, and/or the CyberEd lesson on mixtures to list examples of mixtures for question 4. http://videos.howstuffworks.com/hsw/8396-physical- science-series-mixtures-video.htmhttp://videos.howstuffworks.com/hsw/8396-physical- science-series-mixtures-video.htm (IF VIDEO DOESN’T SHOW…Just skip it!)