THE NATURE OF SCIENCE

INTEGRATED SCIENCE

MS. WACK

In this section you will learn the basics of scientific investigations, including the scientific method, graphing, modeling, measuring

and properly reporting your measurements .

Branches of Science

Earth Science: The scientific study of the planet Earth

Life Science: Any science that deals with

living organisms, their life processes, and

their interrelationships.

Branches of Science

Branches of Science

Physical Sciences

1) Chemistry: The study of matter and energy

2) Physics: The study of the interactions between matter and energy

SCIENTIFIC MODELS

Model: An idea, system or mathematical

expression that is similar to the idea being

explained

Model of an Atom Model of a Cell Model of Earth’s Layers

Accuracy

• An accurate measurement is one that is the desired value or is very close to the desired value

• Accuracy: Measurements are close to the actual value

Precision

• Precise measurements are measurements that are close to each other (getting the same measurements every time)

• Precision: Reproducibility or Repeatibility

What is the difference between precision & accuracy?

Precise measurements do not have to be accurate,

but accurate measurements are

always precise!

SCIENTIFIC NOTATION

• A number is written in 2 parts.– The first part is a number

between 1 & 10– The second part is a

power of ten

• Exponent– Positive exponents

represent numbers greater than 1

– Negative exponents represent numbers less than 1

Scientific Notation• To convert a number to scientific

notation:– Count how many places the decimal place

must be moved to make the number a number between 1 & 10 (the coefficient)• The number of spaces the decimal moved is

the value of the exponent– If you moved the decimal to the right, the

exponent is negative– If you moved the decimal to the left, the

exponent is positive– Write: Coefficient x 10exponent

SCIENTIFIC NOTATION

• To convert a number from scientific notation to regular notation:– If the exponent is positive, move the decimal in

the coefficient the number of spaces indicated by the exponent to the right

– If the exponent is negative, move the decimal in the coefficient the number of spaces indicated by the exponent to the left.

SCIENTIFIC NOTATION PRACTICE PROBLEMS

Express the following measurements in scientific notation.453.32________________ 1000_____________________0.0000421_____________ 0.00040___________________

Convert the following to standard notation3.0 x 106______________ 4.4 x 10-7__________________1.49 x 10-5_____________ 3.75 x 102_________________

Perform the following using scientific notation.(9.39x106)x(4.37x10-8) =____________________________(5.12x103)(8.61x104)=____________________________

What do the countries in red have in common?

International System of Units (SI Units)

• A revised version of the metric system that was developed in France in 1795 and was adopted by international agreement in 1960

• There are 7 base SI units– All other SI Units are DERIVED from the 7

base units

Base Units: The 7 metric units that SI is built upon

Physical Quantity

Unit Name Unit Symbol

Measured using…

Mass

Length

Time

Quantity

Temperature

Electric Current Ammeter

Luminous Intensity

Photometer

NON-SI UNITS

Physical Quantity Unit Name Unit Symbol

Volume

Pressure

Temperature

Energy

Derived Units Commonly Used in Chemistry

Physical Quantity

How to Calculate

Unit Name Unit Symbol

Volume

Area

Density

To Derive a Unit• Write the mathematical formula for the quantity.• Replace the formula with units and simplify.

Practice Problems

• Calculate the area of a space having a length of 3.2 cm and a width of 2.1 cm.

• A cube measures 0.02 cm on each side. What is the volume of this cube?

• What is the density of the cube above if its mass is 1 g?

Common US-Metric Conversions

METRIC CONVERSIONS

DIMENSIONAL ANALYSIS

Dimensional analysis is a method used to convert between units

•Uses units that are equal to each other in ratio form to convert between units

2300 seconds x 1 minute x 1 hour x 1 day = .02 days

60 seconds 60 minutes 24 hours

METRIC PREFIXES

METRIC PREFIXESPREFIX In 1 base unit there

are:Example

mega- (M) 10-6 M-unit 1 m = 10-6 Mm

kilo- (k) 10-3 k-unit 1 L = 10-3 kL

deka- (dk) 0.1 dk-unit 1 g = 0.1 dkg

BASE UNIT

deci- (d) 10 d-unit 1 s = 10 ds

centi- (c) 100 c-unit 1 mol = 100 cmol

milli- (m) 1000 m-unit 1 m = 1000 mm

micro- () 106 -unit 1 L = 106 L

nano- (n) 109 n-unit 1 g = 109 ng

pico- (p) 1012 p-unit 1 s = 1012 ps

Steps to Dimensional Analysis1. Start with what you know

(number and unit).2. Times a line.3. Add a conversion factor so that

units cancel and what you are looking for is on top of the ratio.

4. Check your answer.

DIMENSIONAL ANALYSIS

1 Base Unit Equals

10-6 Mega-10-3 kilo-0.1 deka-10 deci-

100 centi-1000 milli-106 micro-109 nano-1012 pico-