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This presentation provides an introduction to the field of chemistry, focusing on the characteristics of matter and the different types of changes that can occur. It also covers measurement units and properties of matter.
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Resources Chapter Presentation Bellringer Transparencies Sample Problems Visual Concepts Standardized Test Prep
The Science of Chemistry Chapter 1 Table of Contents Section 1What Is Chemistry? Section 2Describing Matter Section 3How Is Matter Classified?
Chapter 1 Section1 What Is Chemistry? Bellringer • Make a list of all the chemicals that you can think of. • Which ones on that list could you live without? • Which ones on the list could you not live without?
Chapter 1 Section1 What Is Chemistry? Objectives • Describeways in which chemistry is a part of your daily life. • Describethe characteristics of three common states of matter. • Describephysical and chemical changes, and give examples of each.
Chapter 1 Section1 What Is Chemistry? Objectives, continued • Identifythe reactants and products in a chemical reaction. • Listfour observations that suggest a chemical change has occurred.
Section1 What Is Chemistry? Chapter 1 Working with the Properties and Changes of Matter • A chemical is any substance that has a definite composition. • A chemical reaction is the process by which one or more substances change to produce one or more new substances.
Visual Concepts Chapter 1 Chemical
Section1 What Is Chemistry? Chapter 1 Physical States of Matter • The states of matter are the physical forms of matter which are solid, liquid, gas, and plasma. • Macroscopic refers to what you can see with the unaided eye. • Microscopicrefers to what you would see if you could see individual atoms.
Section1 What Is Chemistry? Chapter 1 Physical States of Matter, continued Properties of the Physical States • Solids have a fixed volume and shape that result from the way their particles are arranged. • Liquidshave a fixed volume but not a fixed shape. • Gaseshave neither fixed volume nor shape.
Chapter 1 Section1 What Is Chemistry? Water in Three States
Visual Concepts Chapter 1 Solid, Liquid and Gas
Section1 What Is Chemistry? Chapter 1 Changes of Matter • Physical changesare changes in which the identity of a substance doesn’t change. • Changes of state are physical changes. • Chemical changesoccur when the identities of substances change and new substances form.
Chapter 1 Section1 What Is Chemistry? Changes of Matter, continued Chemical Changes • mercury(II) oxide mercury + oxygen • Reactants are the substances are the left-hand side of the arrow. • They are used up in the reaction. • Products are the substances are the right-hand side of the arrow. • They are made in the reaction.
Evidence of a Chemical Change Chapter 1 Section1 What Is Chemistry?
Section1 What Is Chemistry? Chapter 1 Changes of Matter, continued Evidence of a Chemical Change • Evidence that a chemical change may be happening generally falls into one of the following categories. • the evolution of a gas • the formation of a precipitate • the release or absorption of energy • a change in temperature or the giving off of light energy • a color change in the reaction system
Visual Concepts Chapter 1 Chemical Reaction
Chapter 1 Section2 Describing Matter Bellringer • Look at the list of words below: • peanut butter, water, fish, light, garbage, time, motion, the human brain, carbon dioxide, air, yourself, an idea, tree, energy • Sort the words into three categories: matter, not matter, or not sure. • Why is a clear definition of matter important to the study of chemistry?
Chapter 1 Section2 Describing Matter Objectives • Distinguish between different characteristics of matter, including mass, volume, and weight. • Identify and use SI units in measurements and calculations. • Set up conversion factors, and use them in calculations.
Chapter 1 Section2 Describing Matter Objectives, continued • Identify and describe physical properties, including density. • Identify chemical properties.
Section2 Describing Matter Chapter 1 Matter Has Mass and Volume • Matter is anything that has mass and volume. • Volume is the space an object occupies. • Mass is the quantity of matter in an object. • Devices used for measuring mass in a laboratory are called balances. • Weight is the force produced by gravity acting on a mass.
Visual Concepts Chapter 1 Comparing Mass and Weight
Section2 Describing Matter Chapter 1 Units of Measurement • When working with numbers, be careful to distinguish between aquantityand itsunit. • Quantity describes something that has magnitude, size, or amount. • Unit is a quantity adopted as a standard of measurement.
Chapter 1 Section2 Describing Matter Units of Measurement, continued Scientist Express Measurements in SI Units • Scientists worldwide use a set of units called the Système Internationale d’Unités or SI.
Chapter 1 Section2 Describing Matter Units of Measurement, continued Scientist Express Measurements in SI Units, continued • Base units can be too large or too small for some measurements, so the base units may be modified by attaching prefixes.
Visual Concepts Chapter 1 SI (Système Internationale d’Unités )
Visual Concepts Chapter 1 Conversion Factor
Section2 Describing Matter Chapter 1 Unit of Measurement, continued Converting One Unit to Another • A conversion factor is a simple ratio that relates two units that express a measurement of the same quantity. • example: You can construct conversion factors between kilograms and grams as follows:
Using Conversion Factors Section2 Describing Matter Chapter 1
Chapter 1 Section2 Describing Matter Converting Units Sample Problem A Convert 0.851 L to milliliters.
Chapter 1 Section2 Describing Matter Sample Problem A Solution • The equality that links the two units is 1000 mL = 1 L. (The prefix milli- represents 1/1000 of a base unit.) • The conversion factor needed must cancel liters and leave milliliters. Thus, liters must be on the bottom of the fraction and milliliters must be on the top.
Section2 Describing Matter Chapter 1 Derived Units • Many quantities you can measure need units other than the seven basic SI units. • These units are derived by multiplying or dividing the base units. • Speedis distance divided by time.The derived unit of speed is meters per second (m/s). • A rectangle’sareais found by multiplying its length (in meters) by its width (also in meters). • Its unit is square meters (m2).
Section2 Describing Matter Chapter 1 Derived Units, continued • Volume is another commonly used derived unit. • The volume of a book can be found by multiplying its length, width, and height. • The unit of volume is the cubic meter (m3). • This unit is too large and inconvenient in most labs. Chemists usually use the liter (L). • 1L = 1000 mL = 1000 cm3
Section2 Describing Matter Chapter 1 Properties of Matter Physical Properties • Aphysical propertyof a substance is a characteristic that does not involve a chemical change. • Physical properties of a substance can be determined without changing the nature of a substance. • Physical properties include texture, state, melting point, and boiling point.
Section2 Describing Matter Chapter 1 Properties of Matter, continued Density is the Ratio of Mass to Volume • Thedensityof an object is the mass of the object divided by volume of the object. • Densities are expressed in derived units such as g/cm3 or g/mL. • Density is calculated as follows:
Chapter 1 Section2 Describing Matter Properties of Matter, continued Density of an Object • The density of a substance is the same no mater what the size of the sample is.
Visual Concepts Chapter 1 Equation for Density
Chapter 1 Section2 Describing Matter Properties of Matter, continued Density Can Be Used to Identify Substances • Because the density of a substance is the same for all samples, you can use this property to help identify substances.
Section2 Describing Matter Chapter 1 Properties of Matter, continued Chemical Properties • Achemical propertya property of matter that describes a substance’s ability to participate in chemical reactions. • A chemical property of many substances is that they react with oxygen. • example: rusting • Some substances break down into new substances when heated.
Visual Concepts Chapter 1 Comparing Physical and Chemical Properties
Visual Concepts Chapter 1 Signs of a Chemical Reaction
Chapter 1 Section3 How Is Matter Classified? Bellringer • Make a list of the ways you have seen things organized. • Which of these methods was the easiest to use and provided the greatest success?
Chapter 1 Section3 How Is Matter Classified? Objectives • Distinguish between elements and compounds. • Distinguish between pure substances and mixtures. • Classify mixtures as homogenous or heterogeneous. • Explainthe difference between mixtures and compounds.
Section3 How Is Matter Classified? Chapter 1 Classifying Matter • Anatom is the smallest unit of an element that maintains the properties of that element. • Matter exists in many different forms but there are only 110 types of atoms. • Atoms are joined together to make up all the different kinds of matter.
Section3 How Is Matter Classified? Chapter 1 Pure Substances • Apure substance is a sample of matter, either a single element or a single compound, that has definite chemical and physical properties. • Elementsare pure substances that only contain one kind of matter. They cannot be separated or broken down into simpler substances by chemical means. • Each element has its own unique set of physical and chemical properties.
Pure Substances Section3 How Is Matter Classified? Chapter 1
Chapter 1 Section3 How Is Matter Classified? Elements are Pure Substances • Each elements is represented by a distinct chemical symbol.
Section3 How Is Matter Classified? Chapter 1 Pure Substances, continued Elements as Single Elements or Molecules • Amolecule is the smallest unit of a substance that keeps all of the physical and chemical properties of that substance. • A molecule usually consists of two or more atoms combined in a definite ratio. • Diatomicelements exist as two atoms of the same element joined together.
Section3 How Is Matter Classified? Chapter 1 Pure Substances, continued Some Elements Have More Than One Form • Some elements, such as oxygen, phosphorus, sulfur, and carbon, have many different molecular forms. • An allotrope is one of a number of different molecular forms of an element. • The properties of allotropes vary widely.
Chapter 1 Section3 How Is Matter Classified? Pure Substances, continued Some Elements Have More Than One Form, continued • Oxygen exists as allotropes. • Oxygen gas (O2) is colorless and odorless. • Ozone (O3) is toxic and pale blue.