Aim: What is matter? Do Now: A cup of gold colored metal beads was measured to have a mass 425 grams. By water displacement, the volume of the beads was calculated to be 48.0 cm3. Given the following densities, identify the metal. Gold: 19.3 g/mL Copper: 8.86 g/mL Bronze: 9.87 g/mL Homework: Go on the School Website. Select “Homework #1 Matter and Properties”. On A separate Sheet of paper record your answer and explain your reasoning for your choice.

Matter Matter is anything that has mas mass and volume Mass and volume are examples of extensive properties Extensive properties are properties that depend on the amount of matter in a sample Intensive properties are properties that depend on the type of matter in a sample, not the amount of matter (i.e., density)

Physical change vs. Chemical Change During a physical change, some properties of a material change, but the composition of the material does not change Physical changes can be classified as reversible or irreversible A new product is not formed Examples: aluminum foil is cut in half, water evaporates from the surface of the ocean, juice freezes During a chemical change, the composition of the matter always changes Chemical changes produce new substances with different chemical make-ups and properties than the original substance. Examples: milk goes sour, gasoline is ignited, your body digests food, metal rusts

Mixtures A mixture is a physical blend of two or more components. Based on the distribution of components, mixtures can be classified as heterogeneous mixtures or as homogeneous mixtures Heterogeneous mixtures are a mixture in which the composition is not uniform throughout. Oil and vinegar, chicken noodle soup Homogeneous mixtures or solutions are mixtures in which the composition is uniform throughout. oil, vinegar, cup of coffee, salt water

Elements and Compounds An element is the simplest form of matter that has a unique set of properties. Oxygen, hydrogen A compound is a substance that contains two or more elements chemically combined in a fixed portion. Salt, sugar Compounds can be broken down into simpler substances by chemical means, but elements cannot.

-Simplest form of matter. Ex: O2 -Particles are not uniformly distributed. Particles are physically combined. -Particles are uniformly distributed. Particles are physically combined. -Simplest form of matter. Ex: O2 -Two or more different elements chemically combined. Ex: H2O

Sample Problems Which substance can not be decomposed into simpler substances? (1) ammonia (2) aluminum (3)methane (4)methanol Answer: choice 2 aluminum is an element. It is a pure substance and cannot be broken down by any means into simpler parts. The other choices are compounds

Sample Problems cont. Which statement describes a characteristic of all compounds? (1) Compounds contain one element, only. (2) Compounds contain two elements, only. (3) Compounds can be decomposed by chemical means. (4) Compounds can be decomposed by physical means. Answer: Choice 3 A compound can be decomposed by a chemical change. It is made of two or more different elements chemically united in a definite ratio.

Sample Problems cont. Which formula represents a binary compound? (1) NH4NO3 (2) CH4 (3) CH3CoCH3 (4) CaCO3 Answer: Choice 2 CH4 is composed of two elements: carbon and hydrogen

Sample Problems cont. An example of a heterogeneous mixture is: (1) soil (2) sugar (3) carbon monoxide (4) carbon dioxide Answer: Choice 1 Soil has minerals, rocks, dirt, bacteria, etc., all mixed together; different parts of the soil have different amounts of materials.