What is Scientific Investigation? Methods of Scientists What is Scientific Investigation?

Can growing plants alter soil? Question Things Many realize that plants grow better in certain soils. Soils can help plants to grow. Can growing plants alter soil?

Hypothesize From prior knowledge, can you predict an answer to my question? Try it now. Start like this If there are many containers of soil and plants are put in half of them and allowed to grow, then I think ……

Identify your Variables Independent Variable is the one thing you deliberately change to see if it will have an impact on something else. Dependent Variable is the one thing you measure to see if it was impacted by the change in the independent variable.

Write Your Procedure Design an experiment that will allow you to test your hypothesis. Write the steps in sequence. How much soil will you use? How often will you water and with how much water? What type of plant? Keep everything else exactly the same except the independent variable. In this way, you will know if that change had a measurable effect. Write down all the materials you will need in the experiment

Data and Graphs Record your data into a table with headings and units Calculate Averages and Deltas Graph the data appropriately (bar, line, circle) page 18 Independent Variable is on the X axis and Dependent is on the Y

Analysis Examine your data in all of its forms. Look for trends and patterns Look for minimums and maximums DO NOT just repeat the data table but, rather, explain what the data is telling you Make statements and show that the data supports those statements

Conclusion Restate your hypothesis and then explain if the data supports it or refutes it Summarize your findings In a new paragraph, explain if you found faults in your design. Explain how they should be fixed.

Use Appropriate Measurements SI (System International or Metric) Length (meters) Mass (grams) Weight (Newton) Area (square meters or centimeters) Volume (cubic meters or cubic centimeters = milliliters) Time (seconds or hours) Temperature (celsius or Kelvin) Density (mass/volume)

Things to Remember Mass is how much matter there is Weight is how gravity pulls on that matter Density is how much matter there is in a certain amount of space. If I cut an object in half it still has the same density because I reduced both its mass and its volume. Temperature is a measure of the movement of atoms or molecules. If it is so cold that atoms stop moving, we call it absolute zero. That is 0 K or -273 C. It is often easier to work with extreme numbers by using scientific notation.

Scientific Notation a coefficient and 10 raised to a power 1 gram of H has 602000000000000000000000 atoms   Use Scientific Notation to make it easy. Write the number as a product of 2 numbers; a coefficient and 10 raised to a power 36,000 is 3.6 x 104 0.0081 = 8.1 x 10-3

STEPS  1. the coefficient must be greater than or equal to 1 and less than 10 (3.6) 2. exponent indicates how many times the coefficient must be multiplied by 10 (4) 3. if the number is greater than 10, the exponent is + and equals the number of places the decimal was moved to the left (36,000 = 3.6 x 104) 4. if the number is less than 10, the exponent is - and indicates the number of places the original decimal point has been moved to the right

Using Scientific Notation in Calculations 1. Multiplication multiply the coefficients and add the exponents (3.0x104)x(2.0x102)=6.0x106 2. Division divide coefficients and subtract the exponents (3.0x104)/(2.0x102)=1.5x102 3. Addition & Subtraction first make exponents the same then add or subtract the coefficients (5.4x103 + 6.0x102) 5.4 x 103 + 0.6 x 103 6.0 x 103

Practice You will now practice these skills. Do Scientific Notation sheet Convert between meters, kilometers and centimeters on the next sheet Tomorrow, you will set up an experiment to answer the question “Do Plants Impact Soil?”