Wednesday, Sept. 4 th : “A” Day Thursday, Sept. 5 th : “B” Day Agenda  Homework Questions/Collect (Pg. 9: 1-10)  Sec. 1.1 Quiz: “What is Chemistry?”  Lab discussion  Sec 1.2: “Describing Matter” Matter, volume, mass, weight Units of measurement (base/derived) Conversions between units Properties of matter: physical & chemical  Homework: 1. Sec. 1.2 review, pg. 19: # Concept Review: “Describing Matter”

Homework Pg. 9: #1-10  Questions?  Collect

Section 1.1 Quiz “What is Chemistry?”  You may use your guided notes and your book to complete the quiz……

“Lab Techniques” Lab Discussion  I just wanted to take a few minutes to go over the lab analysis/conclusion questions so that you know what I expect in future labs…

Sec 1.2: “Describing Matter” Matter: anything that has mass and takes up space.  Sort Into: Matter, not matter, not sure. Peanut butter, water, fish, energy, garbage, time, motion, the human brain, carbon dioxide, air, yourself, an idea, a tree.

The Space an Object Occupies is its Volume  Volume: A measure of the size of a body or region in 3-dimensional space  How to find volume: Solids: (length) X (width) X (height) OR Liquid displacement Liquids: graduated cylinder

The Quantity of Matter is the Mass  Mass: A measure of the amount of matter in an object; a fundamental property of an object that is not affected by the forces that act on the object, such as the gravitational force  How to measure mass: Balances, either mechanical or electronic

Mass is not Weight  Weight: A measure of the gravitational force exerted on an object; its value can change with the location of the object in the universe  Weight and mass are not the same thing!

Weight vs. Mass  If you were on the moon, would your mass change?  What about your weight?

Qualitative vs. Quantitative  Terms such as heavy, light, rough, and smooth describe matter qualitatively. They describe the “quality” of matter but DO NOT use numbers. Scientists describe matter in quantitative terms, using numbers. They describe the “quantity” of matter. Examples: 200˚C, 15 mL, 10 sec

Quantities and Units  Quantity: something that has magnitude, size, or amount  Unit: a quantity adopted as a standard of measurement Example: a graduated cylinder Quantity = the volume of a liquid Unit = milliliter (mL)

Units of Measurement  The 7 BASE UNITS of measurement in the SI system are: (the 1 st 5 are the most common…) “SI” stands for Systeme Internationale d’Unites

Units of Measurement  Sometimes, the base units can be too big or too small for certain measurements, so prefixes are added to the base units.

Converting One Unit to Another  Other equivalent values that you need to know….. 1 L = 1,000 mL = 1,000 cm 3 1 mL = 1 cm 3  Often, volumes are measured in cm 3 and not mL  cm 3 is read “cubic centimeter” or “cc” (think of doctor shows…I need 500 cc’s, stat!)

Converting One Unit to Another  Conversion factor: A ratio that is derived from the equality of 2 different units and that can be used to convert from one unit to the other. **Conversion factors are fractions that are always equal to 1** Example: 1 dozen eggs = 12 eggs The 2 conversion factors are: 12 eggs OR 1 dozen 1 dozen 12 eggs  It’s just like you’re multiplying by 1. Multiplying by 1 doesn’t change the value, right?

Sample Problem A, Pg. 14 Converting Units  Convert L to milliliters, mL. 1.Always “start with what you know”: L 2.Multiply by a conversion factor to get the unit you want. In this case, 1 L = 1,000 mL 3.The unit that you WANT always goes ON TOP of the conversion factor! L X 1,000 mL = 851 mL 1 L

More Conversion Practice  Convert g to kilograms. 1.Always “start with what you know”: g 2.Multiply by a conversion factor to get the unit you want. In this case, 1 Kg = 1,000 g 3.The unit that you WANT always goes ON TOP of the conversion factor! g X 1 Kg = Kg 1,000 g

More Conversion Practice  Convert 17.3 m to centimeters.  Convert 5.13 m to millimeters.

Derived Units  Derived units: units found by multiplying or dividing the 7 base units.  Examples: Speed is m/s (meters divided by seconds) Area is m 2 (length X width) Volume is m 3 (length X width X height)

Properties of Matter  Matter has many properties.  These properties can be classified as either physical or chemical…

Properties of Matter  Physical property: A characteristic of a substance that does not involve a chemical change, such as density, color, or hardness.  Examples color, state, melting point, boiling point, density, hardness, etc.

Density  Density: the ratio of the mass of a substance to the volume of the substance; often expressed as grams per cubic centimeter (g/cm 3 ) for solids and liquids and as grams per liter (g/L) for gases. Density = mass volume  The density of a substance is the same no matter what the size of the sample is.  Density is a PHYSICAL property.

Density can be used to identify substances  As I was walking through the parking lot this morning, I found this necklace. I wonder if it’s pure silver? How could I test it to find out?

Chemical Properties  Chemical property: a property of matter that describes a substance’s ability to participate in chemical reactions.  Examples: Reactivity with oxygen Sensitivity to light

Homework  Sec. 1.2 review, pg. 19: #1-11  Concept Review: “Describing Matter” (Concept Review packet is due day of Chapter test)

Looking Ahead  Next Time: Section 1.2 Quiz: “Describing Matter” Lab Write-up  Wednesday: High School Open House 6:30 – 8:00 pm