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Chapter 1 Introduction to Matter. Section 1: Describing Matter What is Matter?. Matter is the “stuff” that makes up everything in the universe Anything that takes up space and has mass Air, books, milk, statues, fruit, baseball, flowers. What are Characteristic Properties?.
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Section 1: Describing MatterWhat is Matter? • Matter is the “stuff” that makes up everything in the universe • Anything that takes up space and has mass • Air, books, milk, statues, fruit, baseball, flowers
What are Characteristic Properties? • A quality of a substance that never changes and can be used to identify the substance. • Examples: Density, Boiling point, Melting point, Freezing point, chemical activity • Boiling Point (temperature at which a liquid boils) • Pure water has a boiling point of 100°C or 214°F • Melting Point (temperature at which a solid melts) • Ice has a melting point of 0°C or 32°F
Changes in Matter Physical Change Chemical Change • Alter the form of a substance, but not its identity • One or more substances combine or break apart to form new substances. • Chemical activity – the ability to undergo a specific chemical change
Identify the changes in matter. Drag the changes into the appropriate box. Physical Change Chemical Change Heating water on a stove turning it into water vapor Heating an ice cube turning it into water Placing water into a freezer turning it into ice Tearing paper Mixing sugar and water Burning paper Heating sugar turning it into caramel
Types of MatterMatter can be classified into two general categories: Mixtures Pure Substances • A mixture consists of two or more substances that are mixed together but not chemically combined • Orange juice, grape juice • Sea Water is a solution • Solution = “best-mixed” of all possible mixtures (sugar water and salt water) • A pure substance is made of only one kind of matter and had definite properties • Elements and Compounds
Mixtures can be homogeneous or heterogeneous Heterogeneous Homogeneous • Mixtures in which the substances do not spread out evenly. • Mixtures in which substances are spread evenly throughout,
Identify whethere the following mixtures are heterogeneous or homogenoeous . Drag the mixtures into the appropriate box. Heterogeneous Homogeneous Flat soda pop Spaghetti sauce alcohol mayonnaise Aluminum foil Sugar water soil Beach sand iron Vegetable soup Black coffee Oil and vinegar salad dressing Sugar City air paint Chocolate chip ice cream
Pure Substances Elements Compounds • A pure substance that can not be broken down into other substances by any chemical means • Carbon, iron, copper, nitrogen, aluminum, etc. • A compound is a substance formed from chemical combination of two or more different elements • Water: H2O • Carbon Dioxide: CO2 • Sugar: C12H22O11 • Salt: NaCl
Section 2 Measuring Matter
Mass Verses Weight Mass Weight • Amount of matter an object contains • Mass remains the same throughout the universe • Instrument: Triple beam balance • Units: gram • Measure of force of gravity on an object • Since weight depends on gravity, weight will change when you move around the universe • Instrument: Spring Scale • Units: Newton
Volume: the amount of space an object takes up Regular shaped object Irregular shape object • For regular shaped objects the volume can be calculated mathematically • Units: cm3 (mL) • For Rectangular objects and cubes • V=LxWxH • For irregular shaped objects the volume can be found using water displacement • Units: mL (cm3) • Fill graduated cylinder half way and record volume. Place object in graduated cylinder and record the volume of the displaced water. Subtract the original volume from the new volume to find the volume of the object in mLs.
Density • Density is the measurement of how much mass is contained in a given volume. • To calculate density of an object, divide its mass by its volume. • Density = mass Volume • Units for density: g/mL or g/cm3 • The density for pure water is 1.0 g/mL
Density Practice Problems….. • A small cube of wood has a side that measures 3cm and has a mass of 540 grams. What is the density of the cube and will it float in water?
Section 3: Particles of Matter • Atoms are the smallest particles of an element • Democritus – suggested that there were smallest possible “pieces” of everything and that theses pieces couldn’t be divided any further • Dalton proposed the atomic theory • Atoms can’t be broken into smaller pieces • In any element, all the atoms are exactly alike • Atoms of two or more elements can combine to form compounds • Atoms of each element have a unique mass • The masses of the elements in a compound are always in a constant ratio
Atoms and molecules today • a MOLECULE is a group of atoms joined together and act as a single unit • A CHEMICAL BOND is the force that hold two atoms together • Water : H2O is a molecule