Warm Up Direction: Copy down the questions and provide answers. 1.What kind of change is mixing soil with water to create mud? Explain why. 2.Explain why baking bread is not a physical change. 3.Can you fit more atoms of water or lead in this box ? Explain why. Agenda Turn in Lab Mass Quiz Lab Safety Notes Unit 1-2 Lab Food dye and volume Homework Aug 19- Extra credit online due before 10PM

Safety Quiz Do not write on the QUIZ Bubble in your ID #, version # and write your name on the scantron Write your answers on the back for (#15-19)

Unit 1-3 Describing Matter Volume: the amount of space something takes up -solids = the height X length X width of the object -liquids = use graduated cylinder Meniscus

Describing Matter Mass: The amount of matter contained in that object. Mass can be measured using a balance (for most objects) – Mass is not weight! – Weight is the force produced by gravity acting on a mass. This can be different in different places.

Units of Measurement Quantity: Something that has magnitude, size, or amount Unit: a quantity adopted as a standard of measurement -For meaningful descriptions, all quantities must be labeled with units.

Units of Measurement -Since 1960 scientists world-wide have used the SI system of measurement. -SI = Système international d'unités QuantityUnitAbbreviation Distance or Length Meterm Massgramg TemperatureKelvinK Amount of Substance Molemol

Conversion Factors A conversion factor is a ratio that is derived from the equality of two different units and can be used to convert from one unit to the other – Example: 1 kg = 1000 g

Conversion Factors Other Frequently Used Units – Volume 1 cm 3 = 1 mL – Length 2.54 cm = 1 inch – Mass kg = 1 pound

Converting SI Units

Example 1 Express 4 km in meters – Given: 4 km – Find: meters (m) – Plan (conversion factor): 1 km = 1000 m – Solve: 4 km x 1000 m = 4000 m 1 km

Example 2 Express 100 centigram in kilograms – Given: 100 cg – Find: centigrams (cg) – Plan (conversion factor): 100 cg = 1 kg – Solve: 1 g x 100 cg = 100 cg 1 g

Example 3 Convert 12 kilometers to millimeter

Individual Practice Use the stair-step as a tool to guide you through the Unit 1-2 Conversion Factors Worksheet

Volume Lab Part 1: Measure out drops of water into the 10 ml graduated cylinder and record the volume Part 3: -Measure 3ml of colored water from the tube to the 10ml-graduated cylinder -Drop bleach into your color graduated cylinder until it is cleared & record the # of drops # DropsVolume (ml) drops/ml ml/drop Yellow =Red = Blue =Green =

Clean up Procedure Rinse everything out in the sink Put the equipment in the front Clean your lab table

Assignments Summary at least 3 sentences and answer why is it important to include units in your measurement? Finish the Lab handout