1. Chemistry and Manipulating Numerical Data

2. Measurements Numbers on measurements based on numbers all measurements
                                                                                                                                                      
Measurements
Numbers
science is based
on measurements
all measurements
have:
- magnitude
- uncertainty
- units
mathematics is
based on numbers
exact numbers are
obtained by:
- counting
- definition

3. Graphs

4. shows how many of something
Bar Graph
shows how many of something
are in each category

5. Unit 1 Test – Honor’s Chemistry Introduction to Chemistry
2nd Hour
5th Hour
6th Hour
8th Hour
1st Hour
55 B’s
27 A’s
35 C’s
Avg: %
5 D’s 50 45 40 35 30
This is also about what the quarter grades will look like.
September 14, 2007

6. shows how a whole is broken into parts
Pie Graph
shows how a whole is broken into parts
Percentage of
Weekly Income

7. shows continuous change
Line Graph
shows continuous change
Stock Price over Time

8. Elements of a “good” line graph
axes labeled, with units
use the available space
title
neat
Hopefully, students will realize this data makes no sense. As temperature increase – the volume of a gas increases.

9. How to read a graph 7 L ~4 L Interpolate - read between data points
What volume would the gas occupy at a temperature of 150 K?
Extrapolate - read data beyond data points
What volume would the gas occupy at a temperature of 260 K?
Which do you have more confidence in? Why?
7 L
(dependent variable)
Hopefully, students will realize this data makes no sense. As temperature increase – the volume of a gas increases.
~4 L
(independent variable)

10. Graphs Line Graph Bar Graph Pie Graph
Used to show trends or continuous change
Bar Graph
Used to display information collected by counting
Pie Graph
Used to show how some fixed quantity is broken down into parts
GRAPHS
Each graph is used for a specific reason.

11. Line Graph A B C D How does the mass of a penny change with age?
Mass (g)
Mass (g)
Age (Year of Penny)
Age (Year of Penny) C D
LINE GRAPH
Interpolate – estimate a value between data points on graph.
Extrapolate – estimate a value beyond collected data points. Either before or after.
**We have less confidence in data extrapolated than interpolated.
In graph A: all pennies have the same mass (a reasonable hypothesis) - WRONG
Graph B: older pennies have more mass (this may be due to the fact the pick up mass as they get dirty) - WRONG
Graph C: older pennies have less mass (this may be caused by pennies wearing out in circulation) – WRONG
Graph D: correct; pennies before 1982 were made of solid copper, and pennies after 1982 were made of a zinc core and a thin copper coating
Mass (g)
Mass (g)
Age (Year of Penny)
Age (Year of Penny)

12. Bar Graph Chemistry Grades Descriptive title Legend Number of Students
Axis labeled
(with units)

13. Pie Graph
Note on graph of Earth’s crust that the majority of elements making up the Earth’s crust is oxygen and silicon.
This is because they Earth is covered with sand (silicon dioxide (SiO2)).
Aluminum composes a tremendous 7.5% of the Earth’s crust.
Why recycle aluminum?
It takes less energy (resources) to recycle aluminum than mine its ore and refine the ore to extract aluminum .
Bottom line – it is cheaper to recycle the aluminum already mined from the Earth’s crust.

14. Pie Graphs

15. Reviewing Concepts Presenting Scientific Data
How do scientists organize data?
How can scientists communicate experimental results?
What does a given point represent on a line graph?
The density of copper is 8.92 g/cm3. If you plotted the volume in cubic centimeters, what would the slope of the line be?
Prentice Hall Physical Science Concepts in Action (Wysession, Frank, Yancopoulos) 2004 pg 25
Scientists can organize their data by using data tables and graphs.
Scientists can communicate results by writing in journals or speaking at conferences.