1. Chapter 1

2.  Chemistry is the Study of Matter.  Chemistry is concerned with the properties of chemicals and with the changes that chemicals can undergo.

3.  Any substance that has a definite composition – it is always made of the same “stuff”, no matter what state it is in or where you find it.  Some occur naturally, like water, oxygen, and carbon dioxide.  Some are manufactured like polyethylene, acetone, acetaldehyde, and sodium hydroxide.  Some, like aluminum and copper, are taken from natural elements.

4.  Anything that changes chemicals.  A natural part of life.  Chemical reactions are necessary for: ◦ Things to grow ◦ Things to decay ◦ Food to cook ◦ Engines to run ◦ Food to digest

5.  The way that particles are arranged determines the properties of the matter  Most of the matter that we will talk about is in three states: Solids, liquids, and gases

6.  Fixed shape  Fixed volume  Rigid in structure  Slight vibrations  Strong attraction between particles

7.  Fixed volume  Variable shape  Particles slip past one another  Takes the shape of its container  Particles are held together loosely

8.  Variable shape  Variable volume  Particles move independently of one another  Fills any container it occupies  Particles are far apart and are not attracted to each other

9.  The identity of the substance does not change  Change of state can occur – particles speed up or slow down, arrangement of particles changes  Melting, freezing, crushing, dissolving, tearing, chopping, etc.

10.  Identities of substances change and new substances form.  Reactants – substances used in a reaction  Products – substances formed in a reaction  Burning, rusting, precipitate formation (solid substance forms, may be a cloudy liquid), evolution of gas (indicated by bubbles or odor), color change, etc.

11.  Endothermic – This change in matter requires or uses heat. ◦ Melting, boiling ◦ Energy is absorbed ◦ Temperature of substance increases  Exothermic – This reaction releases heat. ◦ Freezing, condensation ◦ Energy is released ◦ Temperature of substance decreases

12.  The Law of Conservation of Matter states that Matter cannot be created or destroyed.  When a change occurs, whether Physical or Chemical, matter is not created or destroyed!

13.  What is a chemical?  Which state of matter has a fixed shape and volume?  Which state of matter has a fixed volume but takes the shape of its container (variable)?  What type of change does not change the identity of the matter?  What term is used to identify the substances you begin with in a chemical reaction?

14.  List four changes that indicate a chemical change might have occurred.  List four changes that indicate that a physical change might have occurred.  What is the Law of Conservation of Matter?  What does endothermic mean?

15.  Anything that has mass and volume.  Volume – the space that an object occupies  Mass – the quantity of matter contained in the object  Weight – is NOT Mass – they are related, but weight is dependent on gravity. Therefore, weight is dependent on location, mass is not. We will use Mass in Chemistry!

16.  Matter is made of atoms  An atom is the smallest unit of an element that maintains the properties of that element

17. Quantity (symbol)Unit (abbreviation)  Length (l)  Mass (m)  Time (t)  Amount of a substance (n)  Electric Current (I)  Temperature  Meter (m)  Kilogram (kg)  Second (s)  Mole (mol)  Ampere (A)  Kelvin (K)

18.  Since 1 gram = 1000 milligrams  We can write it as a conversion: 1 gram OR 1000mg 1000 mg 1 gram

19. Page 14, # 1 - 3

20.  Can be determined without changing the nature of the substance  Color, state, texture, temperature, melting point, boiling point, density  What are the physical properties of ◦ Your desk ◦ Sugar ◦ A sheet of notebook paper

21.  Identified by trying to cause a chemical change  Reactivity with oxygen, reactivity with acid, flammability

22.  Mass divided by Volume  Is not dependent on the size of the sample  Relationship is linear: The slope of a line represents the density of a substance when the volume is plotted on the x-axis and the mass is plotted on the y-axis.  Can be used to identify a substance  Chart on p. 17 gives densities of substances

23.  A piece of tin has a mass of 16.52 g and a volume of 2.26 ml. What is the density of tin?  A man has a 50 ml bottle completely filled with 163 g of slimy green liquid. What is the density of the liquid?  A piece of metal has a density of 11.3 g/ml and a volume of 6.7 ml. What is the mass of the piece of metal?

24.  Pure Substances ◦ Has characteristic properties that can be used to identify it (physical and chemical properties) ◦ Elements – contain only one kind of atom  Can be single atoms or molecules (two or more atoms of the same kind) ◦ Compounds – contain more than one kind of atom  Represented by formulas  Molecules consisting of two or more atoms combined in definite ratios

25.  Mixtures – A sample of matter that contains two or more pure substances ◦ Most foods and air are mixtures. Sugar and salt are not, water is not ◦ Can vary in composition and properties ◦ Homogeneous Mixtures  Pure substances are distributed evenly throughout the mixture (gasoline, air, syrup, tea) ◦ Heterogeneous Mixtures  Substances are not evenly distributed (orange juice, chocolate chip cookie, salad)

26.  Quantitative measurements involve numbers (quantities).  Qualitative measurements involve observations (color, shape, texture)

27.  An Atom is the smallest unit of an element that maintains the properties of that element  An Element is a substance that cannot be separated or broken down into anything simpler  A Molecule is the smallest unit of a substance that keeps all of the properties of that substance (can be made of more than one atom)

28.  Compound – ◦ Chemically joined ◦ Properties different than that of components ◦ Definite ratio of components  Mixture – ◦ Physically mixed together, not chemically joined ◦ Properties of components are maintained ◦ Varying ratio of components

29.  Pure substances  Matter  Mixtures  Compounds  Elements  Heterogeneous  Homogeneous

30.  Separated by physical properties  Filtration, sorting, distillation, evaporation, using magnetic properties  How would you separate the following mixture? Iron filings, sand, water, salt, and pepper