Observation, Inference & Measurement Topic 1: Observation, Inference & Measurement

Observation vs. Inference Information gained by using the 5 senses. Example: * All measurements are observations Inference- Interpretation conclusion or explanation based on observations. Example: * Predictions are inferences

Scientific Notation A way of writing numbers that are very large or very small. Step 1: Change the number to a number between 1 and 10 by moving the decimal point. Step 2: Assign an exponent of 10 equal to the number of places the decimal place was moved. Example: 4,600,000,000 = 4.6 x 109 0.0000054 = 5.4 x 10-6

Measurements- Defn- Comparing an unknown amount to a known amount.

Basic Measurements Measurement Definition Instrument Metric Units Other Units Mass Volume Length Temperature Time Weight

Classification: Grouping of things based on similar characteristics to make them more meaningful and easier to understand. Instrument- Any device used to aid the senses in making observations

Brainstorming What weighs more… A ton of bricks or a ton of marshmallows??? Which is more dense?

Density Mass Volume Density = The mass per unit volume. Formula: Example: Mass Volume Density =

“The Density Pyramid” Examples: M D V

Sample Problems Mass = 34g Density= 8 g/cm3 Volume= Volume= 27cm3 Density =5 g/cm3 Mass=

Factors Affecting Density: Temperature- As temperature increases, density decreases. (indirect relationship) Pressure- As pressure increases, density increases. (direct relationship) Size and shape do not effect density!!!

Most materials have their greatest density in the solid phase Water is the most dense as a liquid at a temperature of 4o C. The density of water is 1g/cm3 Objects made of the same material will have the same density

Difference from the accepted value Percent Deviation: Difference from the accepted value Accepted value X 100 % Deviation = Examples:

Classification- Grouping objects based on similar characteristics. Instrument- Any device used to aid the senses in making observations

Change When the characteristics or properties of a system are altered. Cyclic Vs. Non- Cyclic

Rate of Change Formula: Examples: Change in Field Value Time

The temperature at 8 am this morning was 62o The temperature at 8 am this morning was 62o. At 11am the air temperature was 73o. Calculate the rate of temperature change (include proper units). The elevation of Mount Matice in 1944 was 11,208 ft. In 2009, the elevation had decreased to 11,194 ft. Calculate the rate of change in elevation during this time. (round to the nearest hundreth and use proper units).

Graphing Change The steeper the slope, the greater the rate of change.

Volume Mass Volume Mass MATERIAL A Volume Mass 2 4 3 6 8 12 MATERIAL B Volume Mass 1 3 2 6 4 12 5 15

Volume Mass Volume Mass MATERIAL A Volume Mass 2 4 3 6 8 12 MATERIAL B Volume Mass 1 3 2 6 4 12 5 15

MATERIAL A Calculate the Density represented by the lines plotted on the graph to the right. MATERIAL B

Dynamic Equilibrium- Situations where change is occurring but overall balance is maintained. Examples:

Metric Conversion Kilo Hecto Deca Deci Centi Milli 7405 mm = meters Gram Meter Liter Kilo Hecto Deca BASIC Deci Centi Milli 7405 mm = meters .875 kg = grams

Pollution: Occurs when the concentration of a substance or an energy source becomes high enough to have an adverse (bad) effect on the environment. As the population density increases, the amount of pollution increases

Brainstorm How would you go about determining the density of a liquid?

BONUS: “Situations where change is occurring but overall balance is maintained.” What is this the definition of?

BONUS: Explain what will happen to the density of air when the pressure exerted on it is decreased.