1. Chapter-2: Measurements Dr. Chirie Sumanasekera
CHEMISTRY Lecture_6
Topic: Graphing Data
Dr. Chirie Sumanasekera
9/7/2018

2. 5 basic types of charts (graphs):
Histogram
Circle graph (Pie Chart)
Bar graph
Line graph
Scatter plot (x-y scatter plot)

3. 1. Histograms Have connected bars
Shows the distribution pattern of a continuous data-set

4. 2. Circle graph (Pie chart)
Shows information as a percentage of the total
Frequency (data) is displayed as “slices” of a “pie.” Bigger the slice, larger the amount represented.
Have immediate visual impact and easy to understand
Does not show data trends (Patterns).

5. 3. Bar Graph Easier to read than a data table!
Shows data categories in rectangular bars ( bars are not connected).
Categories are on x-axis
Hight of bars is equal to the frequency of a data-set represented. (shown on y-axis)

6. 4. Line graph Can be used to show the same data of a bar graph
X- axis shows categories and y- axis shows the frequency of each category.
Only one variable is shown (on y-axis)
Data points are connected to each other showing a trend (pattern) over time.

7. 5. (x-y) Scatter plot NOT the same as a line graph
Great for scientific data representation!
Data points are connected using a best-fit line or they can be connected to each other
Shows co-relationships between variables and trends
X- axis shows the independent variable and y- axis shows the dependent variable
Slope = change in y-axis = y2-y1
change in x-axis x2-x1

8. Please complete the questions on Page-2 of LAB4 for home work
End of Chapter (Unit)-2
Please complete the questions on Page-2 of LAB4 for home work