Integ. Science

Assignments

Take Notes: Page 2 – 10/11

Page 18 – 25

Define Key Terms listed on Page 26

Notes-sheet Prompt

Location Due Date

Textbook/ Notebook

Monday

MondayTextbook/ Notebook

Worksheet Today

Qualitative Observations

• Observations that are not mathematical or measurable. Observations made using our senses:

Examples:– Color, shape, size, odor/smell, texture, etc.

• No measurements are used. We use our senses.

Quantitative Observations

• Observations that are obtained through the use of instruments and are mathematical – They have numbers.

• Examples:– Length, area, mass, weight, etc…

• Measurements are utilized.

Math: Language of Science

• Quantitative observations are collected as data and recorded.

• Numerical data allows us to search for patterns and relationships between variables.

• Numerical data can also be plotted on a graph for another way to look at patterns.

Data from Experiments

Let’s talk about the Mice/Nicotine Experiment

Testing relationship between . . . Nicotine and Cancer in mice

Eliminate variables out of our control(i.e. diet, age, etc) by keeping mice the same

What’s our experimental variable again?What is our control group doing?

Group #Amt. Nicotine

(mg)Amt. of Cancerous

Cells

0 0 0

1 10 30

2 20 60

3 30 90

4 40 120

5 50 150

Cancer found in Mice with Nicotine

0

20

40

60

80

100

120

140

160

0 10 20 30 40 50 60

Amount Nicotine (mg)

Am

ou

nt

of

Ca

nc

ero

us

Ce

lls

Fo

un

d

Terminology

• Precision – Reproducibility, Consistency of Measurement

• Accuracy – Closeness to true value

• Reliability – Trustworthiness of measurement, depends on Measurer and the Measuring Device.

• Uncertainty – Questionability regarding the precision, accuracy, or reliability of a measurement or calculation.

Precision and Accuracy

When making measurements in science you want them to be both precise and accurate.

Precision and Accuracy

Precision indicates degree of reproducibility of a measured number. Accuracy indicates how close your measurements are to the true value.

Reliability and Uncertainty

Reliability – Trustworthiness of measurement. It depends on 1) The Measurer and 2) The Measuring Device.

Uncertainty – Questionability regarding the precision, accuracy, or reliability of a measurement or calculation. The last significant number in any measurement is the most uncertain digit

Accuracy and Precision

Significant Figures

• It is important to record the precision of your measurements so that other people can understand and interpret your results.

• A common convention used in science to indicate precision is known as significant figures.

• Significant figures are those digits in a measurement that are known with certainty plus the first digit that is uncertain.

Significant Figures

Even though this ruler is marked in only centimeters and half-centimeters, if you estimate, you can use it to report measurements to a precision of a millimeter.

Rules for Sig Fig

Rule 1

Zeros between other nonzero digits are significant.

Examples

a. 50.3 m has three significant figuresb. 3.0025 s has five significant figures

Rules for Sig Fig

Rule 2

Zeros in front of nonzero digits are not significant.

Examples

a. 0.892 has three significant figuresb. 0.0008 s has one significant figure

Rules for Sig Fig

Rule 3

Zeros that are at the end of a number and also to the right of a decimal point are significant.

Examples

a. 57.00 g has four significant figuresb. 2.000 000 kg has seven significant figure

Rules for Sig Fig

Rule 4

Zeros that are at the end of a number but left of the decimal point are not significant.

Examples

a. 100 m has ONE significant figureb. 20 m has ONE significant figure

Rules for Sig. Fig.

Extra Rule

Zeros that are at the end of a number but left of the decimal point that are measured to be significant are indeed significant.

Examples

a. A scale measures 1200. kg has four significant figures and is written in scientific notation:

1.200 x 10 kg so Rule 3 applies3