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Energy and Matter 1 The three major temperature scales. Room Temperature 70 F or 21 C Absolute Zero K = C + 273 C = K - 273 2 3 The three states of water: 4 Changes in Matter Physical changes Crushing, tearing, cutting Physical Properties Boiling point, Freezing point, color, state Can be observed without changing substance’s composition Chemical changes Burning, cooking, chemical reactions, rusting In chemical reactions: Color change, precipitate, bubbling, gas produced, smell Chemical Properties Reactivity in a chemical reaction 5 The three forms of the element carbon: These are Allotropes! 6 Chapter 1 Basic Building Blocks of Matter • An atom is the smallest unit of an element that maintains the chemical identity of that element. • An element is a pure substance that cannot be broken down into simpler, stable substances and is made of one type of atom. • A compound is a substance that can be broken down into simple stable substances. Each compound is made from the atoms of two or more elements that are chemically bonded. Chapter 1 Classification of Matter • A mixture is a blend of two or more kinds of matter, each of which retains its own identity and properties. • mixed together physically • can usually be separated • Homogeneous mixtures are called solutions • uniform in composition (salt-water solution) • Heterogeneous mixtures • not uniform throughout (clay-water mixture) Chapter 1 Section 2 Matter and Its Properties Classifying Matter The organization of matter Substances Matter Can be Separated Physically Mixture of Substances Can be Separated Chemically Element Compound Homogeneous Mixture (Solution) Heterogeneous Mixture 10 Chapter 1 Types of Mixtures Twenty-four-karat gold is an element Eighteen-karat gold is an alloy. Fourteen-karat gold is an alloy. 12 Filtration separates a liquid from a solid. 13 No chemical change occurs when salt water is distilled. 14 Separation of a sand-saltwater mixture. 15 Distillation 16 Electrolysis, the decomposition of water by an electric current, is a chemical process. 17 A Mixture: The composition of air. 18 Density Density = Mass Volume kg m3 g kg cm3 L Low density mass immersed in higher density fluid rises High density mass immersed in lower density fluid sinks Tank of water. 20 Person submerged in the tank. 21 Difference Between Mass and Weight Mass is the measurement of the amount of matter in an object Weight depends on the gravity where the mass is located Your mass is the same on the moon or earth You will weigh 1/6 as much as on the moon as on the earth The gravity on the moon is 1/6 that of the earth 22 Energy Potential Energy depends on an object’s position Kinetic Energy depends on an object’s motion 23 Forms of Energy •Thermal Energy •Electrical Energy •Chemical Energy •Nuclear Energy •Electromagnetic Energy Matter Anything that has mass and volume Four states of matter Example Shape Density When Pressurized Gold Retains Shape High Little Change Water Takes Shape of Container High Little Change Gas Nitrogen Takes Shape of Container Low Compresses under Pressure Plasma Interior of Sun Low Compresses under Pressure Solid Liquid Contained by magnetic field 25