Chapter 1 Chemistry: The Science of Matter Fill in the blanks in your notes with the words bolded in orange.

The Scientific Method

 The scientific method is the systematic approach used in scientific study.  Observation : is the act of gathering information by using your senses on a macroscopic level.  Hypothesis : is a testable prediction used to explain an observation (if, then).  Experiment : is a set of observations used to test a hypothesis.  Control, independent variable, dependent variable  Conclusion : addresses whether or not the hypothesis is supported by the results found

The Scientific Method  Theory : is an explanation based on many observations and supported by the results of many experiments.  Scientific law : is a fact of nature that is observed so often that it is accepted as the truth.

Benchmark If you haven’t done so already, you can now begin to do homework #1. Review slides 2-4 and your notes to help you answer these questions. You will not find the answers in your book.

Matter & its Properties  Chemistry is the science that investigates and explains the structure and properties of matter.  Matter is anything that takes up space and has mass.  Mass is the measure of the amount of matter that an object contains.  The properties of matter describe the characteristics and behavior of matter, including the changes that matter undergoes.

Matter & its Properties Physical Properties Example  Characteristics that a sample of matter exhibits without any change in its identity.

Matter & its Properties Chemical Properties Example  The ability of a substance to combine with or change into one or more other substances.

Matter & its Properties

Macroscopic Microscopic  Matter that is large enough to be seen.  Matter that cannot be seen with the naked

Matter & its Properties Qualitative Quantitative  An observation that can be made without measurement.  An observation that uses measurement.

Benchmark If you haven’t done so already, you should read pages 3-15 in your textbook. With the reading, slides 6-11, and your notes should be able to complete homework #2.

Classifications of Matter

Mixtures & Physical Changes Heterogeneous Mixture Homogeneous Mixture  A mixture with different compositions.  A mixture that is the same throughout.  It is also referred to as a solution.

Mixtures & Physical Changes

 Types of Solutions…  Solid Solutions:  Alloys are solid solutions that contain different metals and sometimes nonmetallic substances.  Liquid Solutions:  The solute is the substance that is being dissolved.  The solvent is the substance that does the dissolving.  When the solvent is water, the solution is called an aqueous solution.

Mixtures & Physical Changes  A mixture is a combination of two or more substances in which the basic identity of each substance is not changed.  Mixtures can be separated into its components by physical processes.

Mixtures & Physical Changes  Separation Techniques…  Filtration  Used to separate a mixture with widely varying particles size.  Distillation  Used to separate a liquid mixture.  Crystallization  Used to separate an aqueous solution.  Chromatography  Separates a mixture based on polarity.

Benchmark If you haven’t done so already, read pages With the reading, slides #13-18, and your notes, you should be able to complete homework #3.

Mixtures & Physical Changes  A physical change is a change in matter that does not involve a change in the identity of individual substances.  Matter exists in one of three states ( solid, liquid, or gas ) depending on its temperature.  Any change in state is a physical change.  If a substance is described as being volatile, it becomes a gas easily at room temperature.

Substances & Chemical Changes Compounds Elements  This type of pure substance can be broken down into simpler substances.  It is a chemical combination of two or more different elements joined together in a fixed proportion.  This type of pure substance cannot be broken down into simpler substances.  They are the simplest form of matter.

Substances & Chemical Changes

 The properties of a compound are different from the properties of the elements that compose the compound.  A formula is a combination of the chemical symbols that show what elements make up a compound and the number of atoms of each element.  A substance is matter with the same fixed composition and properties.  Things that are pure are made up of only one kind of matter.  Compounds can be separated into their component elements by chemical means.

Substances & Chemical Changes  A chemical change is a process that involves one or more substances changing into new substances.  It is also referred to as a chemical reaction.  The law of conservation of mass ( matter ) says that in a chemical change matter is neither created nor destroyed.

Substances & Chemical Change  Chemical changes involve an energy change.  Energy is the capacity to do work.  Work is done whenever something is moved.  Chemical reactions that give off heat energy are called exothermic reactions.  Chemical reactions that absorb heat energy are called endothermic reactions.

Density  Density is a physical property of matter.  Density is the amount of matter (mass) contained in a unit of volume.  The density of solids and liquids is usually measured in grams (mass) per milliliter (volume).  g/ml  For irregularly shaped objects, water displacement is used to obtain a volume measurement.  Formula:

Density  Examples…  What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm 3 ?  I threw a plastic ball in the pool for my dog to fetch. The mass of the ball was 125 grams. What must the volume be to have a density of g/ml? I want the ball to float, of course!

Benchmark If you haven’t done so already, read pages With the reading, slides #20-27, and your notes, you should be able to complete homework #4. Be proud of yourself, you just made it through your first unit in chemistry!