Elements, Compounds, and Mixtures

3 Kinds of Matter Elements Compounds Mixtures

Elements All (living and nonliving) of the different kinds of matter in the universe is made from about 100 different substances, called elements. Elements are called the building blocks of matter because all matter is composed of elements. Each element is made up of the same type of atoms.

Compounds A compound is a substance made of two or more different kinds of elements chemically combined in a specific ratio. Each compound is represented by a formula that uses symbols to identify which elements are present. A formula shows the ratio of elements in the compound. H2O – ratio of Hydrogen is 2:1 Oxygen

Compounds The symbols make up the formula. A formula is just chemical shortcut for the compound. The subscript lets us know how many atoms are present. The coefficient lets us know how many molecules are present.

Molecules A molecule is formed when two or more atoms join together chemically. Hydrogen – H2 Oxygen – O2 Diatomic molecules are made of two atoms of the same element.

Molecule The smallest bit of each of these substances would be referred to as a molecule. For example, a single molecule of molecular hydrogen is made from two atoms of hydrogen. A single molecule of water is made from two atoms of hydrogen and one atom of oxygen.

What is the difference between a compound and a molecule? All compounds are molecules but not all molecules are compounds. Molecular hydrogen (H2), molecular oxygen (O2) and molecular nitrogen (N2) are not compounds because each is composed of a single element. Water (H2O), carbon dioxide (CO2) and methane (CH4) are compounds because each is made from more than one element.

Mixtures Most matter in the universe is found in mixtures. A mixture is made from two or more substances either elements, compounds or both - that are not chemically combined.

Heterogeneous Mixture A mixture in which different materials can be easily distinguished. Pizza, dry soup, chex mix, and trail mix

Homogeneous Mixture Homogeneous mixture is a substance in which two or more substances are uniformly spread out. For example salt water. Solution is another term for homogeneous mixture.

Solutions Solute is the substance being dissolved. Solvent is the substance that dissolves a solute. Solubility is the amount of a solute that will dissolve in a solvent. Example: Salt water Solvent: Water Solute: Salt

Molecular Examples Water (H2O) Carbon Dioxide CO2 An oxygen atom can bond with two hydrogen atoms to make a molecule we call water. Water is an example of a compound, because it contains more than one kind of atom. The formula for water is H2O, meaning there are two hydrogen atoms for each oxygen atom. Carbon Dioxide CO2 Carbon dioxide molecules are made from one carbon and two oxygen atoms joined together by covalent bonds. The chemical symbol is CO2.

Molecular Examples DNA Kinetic Theory of Matter Is a large molecule made up of carbon, hydrogen, nitrogen, oxygen, and phosphorous. Kinetic Theory of Matter The idea that all matter is made up of constantly moving tiny particles.

Molecule When a compound is broken down into its’ smallest piece it is called a molecule. You should be able to write the formula for the following: Water - Oxygen - Carbon Dioxide -