FOUNDATIONS OF CHEMISTRY CHAPTER 7.1 CLASSIFYING MATTER Marshall-Arts

Big Ideas Understanding Substances Atomic Structure There are millions of different substances in the world. Each one has a unique set of physical and chemical properties. A substance is either an element or a compound. An element, such as carbon or oxygen, contains only one kind of atom and is found on the periodic table. A compound, such as water or sugar, contains atoms of two or more different elements chemically bonded together. An element is defined by the number of protons in the nucleus of an atom, which determines its characteristics. Atoms can gain or lose electrons (becoming ions) or have different numbers of neutrons (isotopes) and still retain their identity. Electrons are important in terms of chemical properties because they are involved in bonding and balancing the charge of protons. Neutrons are important for determining atomic masses and in the area of nuclear chemistry.

Big Ideas Classification of Matter Compounds vs Mixtures The ability to classify matter into four groups - elements, compounds, heterogeneous mixtures, and homogeneous mixtures - is beneficial. Because there are millions of types of matter, having a way to organize the different types makes it easier to understand the relationships among various forms of matter. Understanding substances helps in understanding mixtures because the properties of each substance can affect the properties of mixture. It can be difficult to obtain a pure compound because natural sources of substances are often mixtures. A compound contains atoms chemically bonded together. A mixture contains substances that are physically blended, but not chemically bonded. In a homogeneous mixture, the substances mix evenly. In heterogeneous mixture they do not mix evenly.

Mini-Lab - “What’s the Matter?” An object made of paper bound together might be classified as a book. Pointed metal objects might be classified as nails or needles. Question: How can you classify an item based on its appearance? Directions: Discuss how you might separate the objects into groups with different characteristics: (ex. Shapes, materials, color, weight etc.) Record your groupings and descriptions in your lab notebooks. Choose one person to share with the class during discussion time.

Vocabulary Anything that has mass and takes up space. Matter - Atom - Substance - Anything that has mass and takes up space. A small particle that is a building block of matter. Matter with composition that is always the same. Element - Compound - A substance that consists of just one type of atom. A type of substance containing atoms of two or more different elements chemically bonded together.

Vocabulary Anything that has mass and takes up space. Mixture - Heterogeneous mixture - Anything that has mass and takes up space. A type of mixture in which the individual substances are not evenly mixed. Dissolve - Homogeneous mixture - To form a solution by mixing evenly. A type of mixture in which the individual substances are evenly mixed.

Concept Map Task Directions: Cut out your circle terms and organize on your handout by making a concept map showing how matter is divided. We will be adding notes on this sheet *paper managers, come and get one sheet for each person in your group.

MATTER handout Anything that has mass and takes up space. Matter on Earth is made up of atoms. Two classifications of matter: substances & mixtures. MATTER

Atoms Parts of an atom. Draw this in your notebook. Quick Facts: - not all atoms have the same number of protons, neutrons and electrons. - atoms are very small (a million times smaller than the diameter of a strand of hair) - nucleus is at the center of the atom and contains protons (+charge) and neutrons (no charge). - electrons (- charge) and move around the nucleus. Parts of an atom. Draw this in your notebook.

Substance handout Matter with a composition that is always the same. Two types of substances: elements & compounds. Substance

A given substance is always made up of the same combination(s) of atoms. Aluminum, oxygen, water, and sugar are examples of substances. Any sample or amount of water is always made up of the same type of atoms. Substances can either be elements or compounds. Substances

Element handout Consists of just one type of atom. Organized on the periodic table. Each element has a chemical symbol. Element

Compound handout Two or more types of atoms bonded together. Properties are different from the properties of the elements that make it up. Each compound has a chemical formula. Compound

Mixtures are combinations of two or more substance that are physically blended together. The substances in a mixture do not combine chemically. They can be separated by physical methods such as filtering. Mixtures Mixtures can be separated into substances by physical methods. Substances physically combine to form mixtures. handout

Mixtures handout Matter that can vary in composition. Substances in mixtures are not bonded together. Two types of mixtures: heterogeneous & homogeneous Mixtures

Heterogeneous mixture handout Two or more substances unevenly mixed. Different substances are visible by an unaided eye or a microscope. Heterogeneous mixture

Homogeneous mixture (solution) handout Two or more substances evenly mixed. Different substances cannot be seen by an unaided eye or even by a microscope. Homogeneous mixture (solution)

Solutes dissolve in the solvents. More about solutions Solvent - Solute - The substance in the largest amount in the solution is the solvent. All other substances in the solution are called solutes. Solutes dissolve in the solvents. Ex. salt dissolves in water to make salt water.

Homework Complete the handout (copy located in google classroom) Complete questions on page 237 in the textbook (1-8)

How do compounds and solutions differ? Because water is a compound, its composition does not change. Pure water is always made up of the same atoms in the same combinations. (same recipe) Therefore, a chemical formula can be used to describe the atoms that make up water (H2O). Salt water is a homogeneous mixture, or solution. The solute (NaCl) and the solvent (H2O) are evenly mixed but are not bonded together. Adding more salt or more water only changes the amounts of the substances. In other words, the composition changes. Because composition can vary (recipe can change) in a mixture, a chemical formula cannot be used to describe mixtures.