1. Mr. Burkholder soburkho@smsd.org Ch 1.3 PowerPoint Notes soburkho@smsd.org

2. Review material

3. Chemistry is the study of the composition and structure of matter and the changes that matter undergo

4. Matter is anything that has mass and takes up space

5. Matter is anything that has mass and takes up space. Do not CONFUSE with Volume. Volume just measure amount of Space, usually in Liters or m 3. Matter has Physical and Chemical Properties.

6. Physical property is observed or measured w/o changing the substance melting, boiling, bending, hardness

7. Chemical property – ability of a compound to undergo a chemical change (reactivity) rusting, burning, decomposing

8. Hypothesis is a proposed explanation for an observable phenomenon “educated guess”

9. Theory Well tested explanation for a broad set of observations Law A theory that is proven to be true.

10. Qualitative measurements- descriptive nonnumeric form example:

11. Quantitative measurements- definite form, numbers ex:

12. New material

13. Accuracy- closeness of a measurement to the actual value, correctness, or truth. How long are these pencils?

14. Precision- How close the measurements are to each other or 12.5cm is more precise then 12cm

15. Precision- How close the measurements are to each other or 12.5cm is more precise then 12cm (Similar to # of decimal places) Which is more precise? A.) 3 B.) 3.14 C.) 3.14159265

16. Precision- How close the measurements are to each other. For a GROUP of numbers, the smaller the range, the more precise. Which is more precise? A.) 3, 4, 5 B.) 3.14, 6.27, 9.14 C.) 3.14159265, 6.276584, 9.14159265

17. Precision- How close the measurements are to each other. For a GROUP of numbers, the smaller the range, the more precise. Which is more precise? A.) 3, 4, 5 Ans Range = 5-3 = 2 (Closest Grouping) B.) 3.14, 6.27, 9.14 Range = 9.14-3.14 = 6 C.) 3.14159265, 6.276584, 9.14159265 Range = 6

18. Explain accuracy and precision for each of the three targets?

19. Scientific notation is a way of expressing a value as the product of a number between 1 and 10 and a power of 10.

20. Which one is wrong?? A.) 1.2 x 10 4 m B.) 1.4 x 10 -7 g C.) 39 x 10 4 m/s First number is between 1.0 and 9.9

21. Exponent on 10: The exponent is how many places the decimal point moves. Positive exponent: the number is > 1 Negative exponent: the number is < 1

22. 0.0001 = 1 x 10 -4 0.00045 = 4.5 x 10 -4 5.4= 5.4 x 10 0 0.000000001= 1 x 10 -9 45000000 = 4.5 x 10 7 The exponent on 10 is the number of digits that the decimal point is moved.

23. SI units

24. Volume =space occupied by an object= (m 3 is official, L is not)

25. Mass = amount of matter in an object= kilogram (kg) we often use grams

26. Measurements only have value if they are based on a agreed upon standard

27. Adopting SI units Many citizens resist the switch to SI units because they have grown up using such units as feet, pounds, and gallons. They are more comfortable with them. Industry leaders point out that such a changeover would require them to replace or convert their machinery a very costly process.

28. BenefitsCitizens in favor of adopting SI argue that because SI is based on powers of 10, conversion and calculations would be easier. Example, how many square feet are in an acre? A benefit to industry is that if we had SI standards for our goods we could sell them to other countries, nearly all of which use SI units.

29. Length = meters (m)

30. Mass = kilogram (kg)

31. Time = seconds (s)

32. Temperature = Kelvin (K) Kelvin is Celsius plus 273. There are no negative numbers in Kelvin Scale.

33. Volume = m 3, Meters Cubed we will often use liter (L)