Bell Work 08/13/2012Write question and answer in notes

• What are the steps to the scientific method?

Unit 1

Essential QuestionWhat tools, skills, and knowledge are needed to conduct scientific inquiry?

What is the purpose of the scientific method?

• Logical approach to solving problems by observing and collecting data, formulating hypothesis, testing the hypothesis, and to formulate theories that are supported by data

Observation vs. Inference

Observation• What you see• May also be based on

senses

Inference• Conclusion or assumption

made by using context clues/observations

Hypothesis

• If, then statement• Example: (I have a headache)– If I take an aspirin; then, I will no longer have a

headache.

Deductive vs. Inductive reasoning

Deductive Reasoning• General Specific• Example: All bachelors are

single men. Johnny is a single man. Therefore, Johnny is a bachelor.

Inductive Reasoning• Specific General

Qualitative vs. Quantitative Qualitative Data

– Description of observation– Sky is blue (color)

Quantitative Data

– Numerical value– Copper ore has a mass of 25.7– Readings of mass,

temperature, volume

Experiments

• Variable– A quantity that can have more than a single value

• Independent variable• Dependent variable• Constant– Factor that does not change when other variables

change• Control– Standard by which test results can be compared to

Independent vs. Dependent Variables

Independent VariableVariable is manipulatedThis is the causePlotted on x-axis

Dependent Variable• Response• The effect• Plotted on the y-axis

Exit Slip08/13/2012

• Differentiate between qualitative data and quantitative data.

Bell Work08-14-2012

• Please write question and answer.Differentiate between scientific law and

scientific theory. A theory can change if its supporting data

changes. A law is assumed to be true and doesn’t change. Also, a law tells what

happens but does not explain why. Theories try to explain why things happen.

SI Unit

• Standards of measurement– Standard: exact quantity that people agree to use

for comparison• Constant values• Easy to preserve and reproduce• Practical in size

Direct Measurements

• Base Units– Mass; kilogram; kg– Length; meter; m– Time; seconds; s– Temperature; Kelvin; K– Electric current; ampere; A– Amount of substance; mole; mol

SI unit Prefixes

• kilo- 1000• hecto-100• deka-10• BASE UNIT-1• deci-.1 (10)• centi-0.01 (100)• milli-0.001 (1000)• micro-0.000001 (1000000)• nano-0.000000001 (1000000000)

Conversion Factors

• Used to change one unit to another• We use dimensional analysis to convert

between units

Teacher Example

• 42g = kg

Class Practice

• 3.61 ml = L

You Practice

• 8 m = cm

Derived SI Units

• What are derived units?– Combinations of SI Base units by multiplying or

dividing standard units• Table 3 page 36

Formulas You Should Know

• Volume (V) = length x width x height– Cubic meter or m³– 1 cm³/1 mL

• Density (D) = mass/volume– Kilograms per cubic meter or kg/m³

• Molar mass (M) = mass/amount of substance– Kilograms per mole or kg/mol

What is density?

• Ratio of mass to volume “how much stuff you have in a given space”

• kg/m ³ is too large of a value to work with in the lab; so, often expressed as g/cm³, g/ml, and for gasses g/L or kg/L.

Rules to follow for working math problems

1. Write down all the information that is given in the problem and put a box around it. This is your “given box”

2. Write the equation that you are going to use to solve the problem.

3. Manipulate the equation if necessary to get the desired variable on the left side of the equal sign

4. Plug in your given and solve5. Box in your answers6. Units must be clearly marked throughout the entire

problem, especially in the answer.

Practice Problem

• A sample of aluminum metal has a mass of 8.4 g. The volume of the sample is 3.1 cm ³. Calculate the density of aluminum.

Given: mass (m) = 8.4 g volume (V)= 3.1 cm ³

Unknown: Density

Practice Problem

• What is the density of a block of marble that occupies 310 cm ³ and has a mass of 853 g?

• 2.75g/cm

Practice Problem

• Diamond has a density of 3.26 g/cm³. What is the mass of a diamond that has a volume of 0.351 cm ³?

• 1.14 g

Practice Problem

• What is the volume of a sample of liquid mercury that has a mass of 76.2 g given that the density of mercury is 13.6 g/mL?

• 5.60 mL

Science, Technology, Society

• Baby born today is expected to live 30 yrs longer than a baby born 100 yrs ago.

Chemistry has made this possible by:• Manufacturing of vaccines and antibiotics• Increased understanding of human nutritional

needs• Fertilizers in argriculture

Nutrition

• Keeps food fresher longer• Refrigeration, pasteurization, drying, salting,

add preservatives • Chemical techniques give fatty acids, amino

acids, amino acids, vitamins, and minerals

Everyday Applications

• Does adding salt to water while boiling make the water boil faster?

• Antacids• Yeast• A lot of chemical technology that saves lives or

improve quality of life has had a negative impact on environment.

• Ex: fossil fuels, acid rain, ozone layer