- Scientists have learned how to use compounds to make our lives easier.
- Crude oils make our likes easier. Examples of crude oils and petroleum, gasoline, kerosene, lubricating oils, diesel fuel, heating oil, and light fuel gases.
- Hydrocarbons are molecules that are composed of hydrogen and carbon.
- Rubber is a flexible material that is formed from long string of hydrocarbons. An example of this is car tires.
- Plastics are made from long strings of carbon with oxygen, nitrogen, chlorine, or sulfur. When heat to applied, plastics can be formed into different shapes.
- Cloth and fabric are made from fibers woven together. Some cloths and fabrics are prepared with natural compounds like wool or cotton. Some other man-made compounds are polyester and nylon.
We can test compounds by using properties, physical and chemical.
Physical properties are density, freezing, melting and boiling points, and color.
We can test this by using these properties. Potassium compounds have violet flames and Sodium compounds have bright yellow flames.
- Compounds are sometimes named with and -ide at the end if there are only two elements present.
- At times, prefixes like mon-, di, or tri- are added to the element names.
- Chemical formulas have symbols that show you which elements have combined to form that particular compound.
- Subscripts tell you the number of atoms that have combined.
- Sugar is made up of six carbon atoms, 12 hydrogen atoms, and six oxygen atoms combined.
- Carbon dioxide is made up of one carbon atom and two oxygen atoms.
- Water is made up of one oxygen atom and two hydrogen atoms.
A chemical change is the change of matter which results a new substance than the original substances.
- An example of chemical change is rust, or iron oxide. Rust is formed with oxygen and iron. However, the rust does not have the same properties as oxygen and iron. The color of the iron has changed.
A compound is formed when the atoms of two or more elements combine.
- An example of a compound is sugar. Sugar molecules form when atoms of carbon, hydrogen, and oxygen chemically combine.
