Conceptual Chemistry

1. Use examples to explain the various branches of science.

2. Diagram and explain the various components of experimental design.

3. Convert units using dimensional analysis.

Use examples to explain the various branches of science.

1.Biological

2.Physical

3.Earth

The study of living things. (bio = life) Video Example 1

Video Example 2

The study of non-living materials and or energy. Video Example 1

Video Example 2

The study of non-living earthfeatures. Video Example 1

Video Example 2

Link 1

Link 2

Link 3

Diagram and explain the various components of experimental design.

Used for formal research.

1.) State the problem.

Usually a question about what you want to learn.

2.) Research the topic.

What is already known?

3.) Form a hypothesis.

Hypothesis = an educatedprediction or solution based on your research.

If… then… because…

4.) Set up the experiment.

Include the materials and procedures.

Change only 1 variable.

Control: Normal, unchanged part

Experimental Group: Changed part

▪ Independent Variable: “I” change the “I”ndependent variable.

▪ Dependent Variable: depends on your change.

Constants: everything that is kept the samebetween the control and experimental group

5.) Collect data.Charts and graphs are good.

6.) Form a conclusion.Accept or reject your hypothesis.

7.) Repeat your work.

8.) Communicate your findings.

1.) Draw a picture of the control group and experimental group. 2.) Label the independent variable.3.) Describe the dependent variable.

Control Group Experimental Group

1.) Draw a picture of the control group and experimental group. 2.) Label the independent variable.3.) Describe the dependent variable.

Control Group Experimental Group

Convert units using dimensional analysis.

Metric Ruler Metric Ruler

Measure and diagram the sheet of paper with the ruler.

Graduated Cylinder

20

30

10 mL 1mL1o sections = section

Graduated Cylinder

Graduated Cylinder Graduated Cylinder

Science uses the metric system. Also called Standard International or

S.I. Units

Quantity Units Symbol Example

Length meters m average human ~ 1.6 m

Mass grams g 1 penny ~ 1 g

Volume Liters L 2 L bottle

Density mass/volume g/mL or g/cm3

density of water ~ 1 g/mL

Temperature kelvin K room temperature = 293 K

Time seconds s 1 min = 60 sec

Pressure Pascals Pa 101,000 Pa = sea level

Nano- n billionth 1/1,000,000,000 DNA

Prefix Symbol

Meaning Multiplied size Example

tera- T trillion 1,000,000,000,000 terabytes

giga- G billion 1,000,000,000 gigabytes

mega- M million 1,000,000 mega million

kilo- k thousand 1,000 10 kilometer race = 7.2 mi

centi- c hundredth 1/100 finger nail

milli- m thousandth 1/1,000 thickness of penny

micro- µ millionth 1/1,000,000 human cells

You must always SHOW WORK when converting units. This will pay off, especially in future science classes!!!

Conversion factor: a fraction with equalamounts on top and bottom, but different units

Equals one

12 inches = 1 foot

Can be used to convert from one type of unit to another.

One step problem: Convert 3 weeks to days.

1.) Start with the number you are given- don’t forget the units!

2.) Write down a conversion factor with the starting units on the bottom and units on top closer to the units you want.

3.) Cross off the same units appearing on the top and bottom.

4.) Repeat steps 2 & 3 until the units you want are on the top of the conversion factor.

5.) Multiply by all of the top numbers, then divide by all of the bottom numbers. Don’t forget the units!

Convert 62 inches to centimeters (1 inch = 2.54 cm)

Convert 75 miles to kilometers (0.62 miles = 1 km)

Two step problem: Convert 3 weeks to hours.

Four step problem: Convert 3 weeks to seconds.

1. How many fingers would be on 12 hands?

2. How many centimeters would be in 200 meters?

3. How many kilometers is 2,043 meters?