Unit 1

Intro to Chem

Metric System or International System (SI) of Measurement

Length/Distance Meter = m

Volume Liter = L

Mass Gram = g

Energy Joule = J calorie = cal

Temperature Degrees Celsius = °C

Pressure Atmosphere = atmPascal = Pa

Time Seconds = s

MILLIMETERS: a dime is about 1 mm thick

METERS: a football field is about 91 m

KILOGRAMS: the mass of a gallon of milk is about 3.77 kilogramsLITERS: a gallon of milk is about 4 liters

MILLILITERS: a teaspoon of medicine is 5mL

VolumeVolume = Measurement of the 3-D

space matter occupiesRead at the meniscus!

Regularly Shaped Solids:

• Ruler: L x W x H• Centimeters cubed

(cm3)

Liquids/Irregular Solids:

• Graduated cylinder or water displacement

• Milliliter (mL)

LengthLength = Measurement of distance

or dimension (L,W,H)– Ruler, meter stick– Centimeter (cm)

Mass vs. WeightWeight

•Measurement of the force exerted on an object by gravity.•Depends on the location and mass.•Measured in Newtons (N)

Mass•Measurement of the amount of matter in an object.•Depends on the number and type of atoms that compose it.•Does not change with location.•Measured in Grams (g)

Graphing Rules

• The title of a graph should always be “The Effect of [independent variable] on [dependent variable].”

• The x-axis of the graph is the independent variable and the y-axis is the dependent variable. In other words, y changes when x changes.

• Units should always be labeled on both axes of the graph.

• The data in the graph should fill the page.

• Abrupt changes in a graph tell you that something significant has happened.

DensityDensity = Measurement of how tightly

the matter within an object is packed together– Density = mass / volume (D = m/v)– Gram/milliliter (g/mL) or

Gram/centimeter cubed (g/cm3)

Metric Conversion Ladder

Steps to using the metric ladder:

1. Find the spot (unit) on the ladder that has the same prefix as the measurement you are starting with.

2. Locate the spot on the ladder that you want to convert your number to.

3. Count the number of steps you must move on the ladder to make your conversion.

4. Move the decimal in your original number this same number of steps and in the same direction (don't forget the Base step).