Earth Science An Introduction
Aim • What is Earth Science and how is it divided?
Earth Science • Earth Science is the study of the Earth • We study the Earth in 4 separate sections • Geology: Study of the history, structure, processes and composition of Earth’s solid surface down to the center • Oceanography: Study of the oceans • Meteorology: Study of the Earth’s atmosphere: weather and climate • Astronomy: Study of the Universe
Quantitative vs. Qualitative Deals with descriptions. Data can be observed but not measured. Colors, textures, smells, tastes, appearance, beauty, etc. Qualitative → Quality • Deals with numbers. • Data which can be measured. • Length, height, area, volume, weight, speed, time, temperature, humidity, sound levels, cost, members, ages, etc. • Quantitative → Quantity Example: Smells good, red cup, strong taste Example: 12oz cup, temp 150 degrees Fahrenheit, cost $2.50
Observation • An Observation is made using your FIVE senses or an instrument • Taste • Touch • Smell • Sight • Hearing The Clouds are white is an observation, WHY?
It is an observation because you used your sense of Sight to make that statement • Make an Observation using your five senses about something in the classroom, Write it down.
Inferences • An Inference is an Educated guess, based on your observations • It will rain today. That is an inference WHY?
It is an inference because it’s only a guess/prediction. • The five senses were not used to determine that it WILL rain If You said it IS raining, would it still be an inference?
Scientists group together similar observations and inferences • This makes the study of objects and events in the environment easier to understand • This grouping is called CLASSIFICATION
Classification Systems • Some classification systems that we study in Earth Science are planets, stars, rocks, minerals, storms
Scientific Method • Ask a question (what are you curious about?) • Hypothesis (Use what you know to make a prediction) “I bet you it works this way..” • Experiment • Method • Observation and collection of data • Analyze data • Draw conclusion (Does it support your hypothesis?)
Accuracy What does it mean if you are asked to record your answer: a. to the nearest tenth Example: 0.1 one decimal place b. to the nearest hundredth Example: 0.01 two decimal places • to the nearest thousandth Example: 0.001 three decimal places
Scientific Notation • Scientific Notation is the scientists “shorthand”. • A simple way to write a very small or large number
Standard form: 1250000 Scientific Notation: 1.25 X 106 exponent Coefficient
Changing Scientific Notation to the actual number • Look at the exponent. If any exponent is a positive number then I am going to move the decimal that number of spaces to the RIGHT! 1.2 x 10³
If the exponent is negative. I will move the decimal that number of places to the LEFT! 1.2 x 10-³
Steps for Converting From:Standard Form to Scientific Notation • Identify the location of the decimal point 1250000. 2. Move the decimal point over to the left and stop before you come to the last number. Count how many spaces you move.
1 250,000. 3. Round to the nearest hundredth. If the thousandths place is a 5 or greater round up/ if it’s less than 5 keep the digit the same. 1.25 4. Multiply this new digit by 10 and raise it to the power to the number of places that you moved the decimal. 1.25 x 10 6 5. If you moved the decimal to the left the exponent is positive. 6. If you move the decimal to the right the exponent is negative.
Scientific Notation Practice • 145700 = _________ • 390000 = __________ • 6.5 x 104 = __________ • 0.006584 = __________ • 5.4 x 10-8 = ________ 1.467 X 103 3.92 x 105 65000 6.584 x10-5 .000000054
Measurement • Length is measured with a meter stick/ruler and has units of meters, centimeters or millimeters. 10 1cm= ____ mm
Conversion Large Small Kids Hate Doing MathDuringCoolMovies metersdecimetercentimetersmillimeters • 750 cm = ____ meters • 2.5 m = ____ mm • 4.3 m = ____ cm • 100 cm =____ m • 1 m = ______mm 1 10 100 1000 7.5 2500 430 1 1000
Area is length x width and the units are cm2. • Volume space object occupies (units are cm3 for solids and mL for liquids) • for a regular solid like a block: length x width x height
Volume of an irregular solid • For an irregular solid like a rock,use the Water displacement method Add water to a graduated cylinder and record Add the object to the cylinder and record Subtract the original volume of water from the water with the object in it
Reading a graduated cylinder • You read the bottom of the meniscus Answer: 21.5 mL
What is the volume of the rock in the picture? Empty graduated cylinder = 200 mL or cm3 Full graduated cylinder = 260 mL or cm3 260 mL – 200 mL = 60 mL or cm3
Mass measures the amount of in an object. Units are grams matter • Density measures the amount of matter that is crammed into an object. • This formula is on pg 1 of ESRT • density = mass • volume • units are g/cm3
Density • What is the density of a mineral whose mass is 60 grams and displaced 40mL of water? Record your answer to the nearest tenth density = mass volume D = 60 g = 40 mL 1.5 _g_ mL
What is the mass of a sample whose known density is 1.5g/mL and a volume of 15 mL? Record your answer to the nearest tenth Mass= 1.5_g_ x 15 mL mL 22.5g
No measurement is perfect • Therefore there must contain some errors • Errors occur for many different reasons… • Write down a few reasons you think errors may occur in taking measurements
%Deviation • In science there are accepted values for certain measurements because nothing is perfect. • Accepted values are determined and will be given to assist in figuring out the percent deviation of a measurement • You can do this for all measurements!!!
So to determine use the Percent Deviation or % Error formula • You need to memorize this formula it is not on the ESRT!!! It will always be expressed as a %
If you find the density of an object to be 1.5g/mL and the accepted density is 1.25 g/mL what is the % deviation? Deviation = 1.5g/mL – 1.25g/mL x 100 = 20% 1.25g/mL
Density measures the concentration of matter in an object • On Page 1 of your ESRT you can find the Formula • Write Down the Formula
The Density of an object DOES NOT depend on the shape or size of the object as long as temperature and pressure remain the same • If you cut a pencil in half each piece is the same density unless you change the temperature or pressure of the object • Example: If I have a cube of graphite that has a mass of 44g and volume of 20 cm3 what is the density? 2.2g/ cm3 (float sink in water?)
Next… I have a graphite ball that has a mass of 88g and volume of 40cm3, what is the density? 2.2g/ cm3 The Density is the same for the two graphite objects Why? Your still working with the same object/material…Graphite!
Physical Changes that affect Density • Pressure • Temperature • Phase Change affect the densities of substances especially those of gasses
1. Pressure and Density • Push molecules closer together and the density will…. increase Important!!!! The space between the molecules is changing NOT THE MOLECULES!!!
Pressure continued… If the pressure of a gas increases, the molecules will come closer together and the density of the gas… INCREASES
Deeper The ocean puts more pressure the _________ you are. Have you ever dove to the bottom of a swimming pool? 3,100 feet of water compressed the tiny air bubbles inside the Styrofoam and turned a large cup into an espresso cup
2. Temperature and Density • Increasing the temperature of a substance (with some exceptions) ___________its density by increasing the volume of that substance. decreases
A hot air balloon expands as you heat the air molecules inside the balloon, creating less pressure so the balloon can rise
Heating the bottom of a fluid can result in convection of the heat to rise from bottom to top of the fluid due to the decrease of the density of the heated fluid.
3. Phase Change and density • The Density of a substance changes with changes in its phase (solid, liquid, gas) • Unlike Water every substance is most dense on it’s _________ form • Water is the most dense as a _______ solid liquid