Warm Up1. You measure an object and find its length to

be 2.48 cm. The actual length according to the package is 2.5 cm.

a. Find the error:b.Find the percent error:

2. If 50 grams of carbon dioxide react completely with 30 grams of water to form carbonic acid, what is the mass of carbonic acid formed?

Warm Up1. You measure an object and find its length to be

2.48 cm. The actual length according to the package is 2.5 cm.

a. Find the error: 2.5 - 2.48 = 0.02b.Find the percent error:

(0.02/2.5) x 100 = 0.8 %2. If 50 grams of carbon dioxide react completely

with 30 grams of water to form carbonic acid, what is the mass of carbonic acid formed?

50 + 30 = 80 grams

Quick Elements “Quiz”

Name the element: Identify the symbol:

Fe NitrogenAg FluorineCu HeliumPb HydrogenS Zinc

Quick Elements “Quiz”

Name the element: Identify the symbol:

Fe: Iron Nitrogen: NAg: Silver Fluorine: FCu: Copper Helium: HePb: Lead Hydrogen: HS: Sulfur Zinc: Zn

Chemistry 3.3 -3.5

International System of Units(SI)

• Revised version of the metric system• Purpose: so that scientists use standard units

of measurement– Important when sharing experimental methods,

following a method, and noting results

Length

• SI unit for Length : meter (m)

Volume

The space occupied by a sample

• SI Unit : Liter (L)

Mass

The amount of matter an object contains

• SI unit for mass: kilogram (kg)

Commonly used Prefixes in the Metric system

You must memorize and be able to use the prefixes indicated in red!!!!

Lets practice

You should know that kilo means 1000 times greater. k = 1000

1 kg is equal to how many grams?1 kg = x g

Lets practice

You should know that kilo means 1000 times greater. k = 1000

1 kg is equal to how many grams?1 kg = 1000 g

If centi- means 1/100or 10-3

Then 1 cm is equal to how many meters?1 cm = ? m

If centi- means 1/100or 10-3

Then 1 cm is equal to how many meters?1 cm = ? m1 cm = 1/100 m = .01 m

If milli means 1/1000

Then 1 L = ? mL

If milli means 1/1000

Then 1 L = 1000 mL

Remember that you have 1000 mL in 1 L, that is where we get the 1/1000!!!

Density

• Density ( ρ ): the ratio of the mass of an object to its volume

• Density = mass volume

ρ = grams L or cm3

Specific Gravity

• Comparison of the density of a substance to another substance (typically water)

• Hydrometer: Device used to measure specific gravity.

TemperatureScales– Celsius

• sets the freezing point of water as 0 ° and the boiling point of water as 100 °

• Includes negative values

– Kelvin • °C + 273 = Kelvin • Absolute zero: 0 K = - 273 C°The point when all molecular motion stops!!!!

– Fahrenheit

Lets practice

Convert 609 K into Celsius:

Convert 25 C into kelvin:

Lets practice

Convert 609 K into Celsius:609 -273 = 336 CConvert 25 C into kelvin: 25 C + 273 = 298 K

The End!!!