04/19/23 1

04/19/23 2

Chapter 1 Matter and energy

04/19/23 3

The Nature of Science

Science Law Fact Hypothesis Theory

Archimedes

04/19/23 4

Scientific method

Observing(Quantitative)(Qualitative)

generalizing

theorizing

testing

04/19/23 5

Types of Data (Recorded observations) Quantitative or qualitative

04/19/23 6

The Role of Hypotheses in Inquiry Tentative answer to a well-framed

question, an explanation on trial Makes predictions that can be

tested

 

                                

04/19/23 7

Hypothesis-Based Science Inquiry that asks specific questions

proposing and testing of hypotheses

04/19/23 8

The Myth of the Scientific Method The scientific method is an

idealized process of inquiry Very few scientific inquiries adhere

to the “textbook” scientific method

04/19/23 9

The Nature of ScienceThe Nature of Science1.1. Science: Science: observationobservation of the world and the of the world and the

constant constant testingtesting of theories against of theories against naturenature, , with the requirement that everything that is to with the requirement that everything that is to be called science must be testable be called science must be testable

The character of science matches the The character of science matches the American characterAmerican character

Practical, pragmatic, classless, based on Practical, pragmatic, classless, based on evidenceevidence

Healthy skepticismHealthy skepticism

04/19/23 10

2.2. Rational approach to questionsRational approach to questions

3.3. Dull slog through failures to reach a Dull slog through failures to reach a conclusionconclusion

4.4. Answers lead to more questionsAnswers lead to more questions

5.5. What is a fact, law, hypothesis, theory?What is a fact, law, hypothesis, theory?

6.6. Can only address question that deal with the Can only address question that deal with the natural world natural world

04/19/23 11

What science is notWhat science is not

PseudosciencePseudoscience

e.g. astrologye.g. astrology

04/19/23 12

04/19/23 13

Limitations of Science

Science cannot address supernatural phenomena

Hypotheses must be testable and falsifiable and experimental results must be repeatable

04/19/23 14

Theories in Science

Broad in scope Generate new hypotheses Supported by a large body of

evidence Explain Incorporates confirmed

observations, laws, and successfully verified hypotheses

04/19/23 15

Law – description of how a natural phenomenon will occur

Fact – natural phenomenon repeatedly confirmed by observation, e.g. Venus takes 225 days to go around the sun

04/19/23 16

Chemistry: The Central Science

chemistry

biology physics

geology ecology

04/19/23 17

Natural Sciences

Biological (biology, ecology) – living things

Physical (chemistry, physics) - nonliving

04/19/23 18

Branches of chemistry

Organic (carbon chemistry)

Inorganic Physical Biochemistry Analytical

04/19/23 19

Matter – anything that has mass & occupies space

Mass – measure of quantity of matter

Weight – measure of Earth’s gravitational attraction for matter

04/19/23 20

Gravity – a product of the bending of spacetime

04/19/23 21

Energy – ability to cause change or ability to do work Kinetic (E of motion) Potential (E of position)

04/19/23 22

Interconversion of matter and energy E = mc2

04/19/23 23

Ecosystems and Energy Flow

All the biotic and abiotic factors in a defined area

04/19/23 24

Energy flows through ecosystems, while matter cycles within them

04/19/23 25

Ecosystems and Physical Laws

Energy is conserved The laws of physics and chemistry apply to

ecosystems Particularly in regard to the flow of energy But degraded to heat during ecosystem processes

04/19/23 26

States of matter

Solid (def. shape and vol.

Liquid (def. vol, fluid)

Gas (neither def. shape or vol.)

Plasma (gas w/ + particles & e-)

04/19/23 27

Physical properties-can be measured w/o chg. In identity (e.g. BP) Extensive – depends on amt.

(e.g.length) Intensive – doesn’t depend on amt.

(e.g. BP)

04/19/23 28

Physical change

Doesn’t result in chg. In identity

04/19/23 29

Chemical properties

Change in identity

04/19/23 30

Chemical change

One or more substances converted into diff. substances

04/19/23 31

Chemical reaction

Reactants Products

04/19/23 32

Indications of chem. reaction Evolution of heat and light Production of a gas Formation of precipitate

04/19/23 33

Reaction types

04/19/23 34

Mixtures- 2 or more kinds of matter, can be separated by physical means

Heterogeneous- not uniform, e.g. vegetable soup

Homogeneous- uniform, e.g. salt water, also called solutions

04/19/23 35

Pure substance- homogeneous sample of matter, e.g. sugar Every sample the same Cannot be separated w/o changing

ID 2 types- elements : cannot be

decomposed by chemical change, and compounds: can be decomposed

04/19/23 36

Law of definite composition A cmpd. contains the same

elements in exactly the same proportions by mass

04/19/23 37

Periodic table

Groups Periods Element symbols, e.g. Fe

04/19/23 38

Types of elements

Metals – luster, reflectors, conduct electricity and heat, ductile, malleable

Nonmetals Metalloids – semiconductors, char.

of both

04/19/23 39