Agenda: 12-16-14: Midterm Review- Science Midterm Wednesday

1. Physical Science S8P1. Students will examine the scientific view of the nature of matter. S8P2. Students will be familiar with the forms and transformations of energy. S8P4. Students will explore the wave nature of sound and electromagnetic radiation. • Agenda: 12-16-14: Midterm Review- Science Midterm Wednesday • Essential Question: How can I strengthen areas of weakness in my progress toward mastering the science standard? • Warm Up: Review and assess your understanding of each standard. • Compare the following diagrams. Which best represents: • an element? 2. molecules? 3. a mixture? • 2. If the molecule below was the product of a chemical reaction and the reactants were SB2 and Hydrogen atoms, how many hydrogen would be in the product? C. B. A.

2. Midterm Review • Check your answer and make corrections or additions as we review. • Raise your hand if you have a question.

3. Which tools are best for volume? Density? Mass? Volume--beakers, graduated cylinders, flasks. Density--graduated cylinders and triple beam balance. Mass--triple beam balance. 2. Use the table below to answer the question. 1981 Pennies 1986 Pennies Mass Volume Mass Volume 4.5 g .8 3.5 g .8 In 1982, the composition of U.S. pennies were changed. According to the chart, how did the pennies change in 1986? The 1986 pennies have a lower mass 4.5 vs. 3.5

4. 3. A spring scale works because the spring stretches the same amount for each additional unit of weight that is hung from it. The chart below shows the length of a particular spring with different weights hanging from it. What would the length be if the weight was 600 grams?  Weight 100 g 200g 300g 400g Length 6 cm 8 cm 10 cm 12 cm 16 cm 4. Alison measured the mass of a sample as 3.12 kg. What is the same mass in grams? 3, 120 grams 5. Cara wants to compare the masses of two different mineral samples. Which would be the best tool to use? triple beam balance

5. 6. What is the main purpose of charts, graphs, and tables? To show information in a clear and precise way. To make reading it easier. 7. What is scientific method? Name 5 of the steps. Scientific Method is the organized method scientists use to investigate problems. Research, hypothesis, experiment, analyze, and form a conclusion. 8. What is a hypothesis? A reasonable and educated guess based on what you know and what you observe. 9. What is a constant? Variables that do not change in an experiment.

6. 10. What is the difference between an independent and dependent variable? Independent variable--variables changed in the experiment. Dependent variable---variables that are changed as a result of the change in  the independent variable. 11. Name the chemical elements that can be found in the following chemical formula: H2SO4 How many atoms? 7 atoms How many molecules? 1 molecule. Extra Understanding: How many elements? 3: Hydrogen, Sulfur, and Oxygen

7. 12. Name the parts of the atom and list what charges they have in a picture. Proton – positive Neutron – neutral Electron – negative

8. 13. Define: atomic number: number of protons in the nucleus of a n atom atomic mass: number of protons + number of neutrons in the nucleus of an atom element symbol: abbreviation example Nitrogen-N or Iron-Fe Draw an example of an element box. atomic number: atomic mass: element symbol:

9. 14. What do groups represent on the periodic table of elements? Vertical column and have similar chemical properties. 15. What do periods represent on the periodic table? Horizontal rows by energy level, increasing atomic number. 16. How do you find the atomic mass? Average number of proton + neutrons.

10. 17. List the properties of metals, nonmetals, metalloids, and inert gases.

11. 18. What is a compound? A pure substance that forms when two or more elements join together. 19. What is the difference between a compound, solution and a mixture?Compound – a substance produced when elements combine and whose properties are different from each of the elements in it. ex. H2O Mixture – a combination of compounds and elements that has not formed a new substance. Ex. Chex Mix (Heterogeneous) Solution – Homogenous mixture.

12. 20. What would you classify lemonade as? Solution 21. What are heterogeneous and homogenous mixtures? Heterogeneous – unevenly mixed- You can see the different substances. Homogenous – evenly mixed- You can’t see the different substances. 22. Define matter. Anything that has mass and takes up space.

13. 23. Define the states of matter and the molecular structure. Solids – molecules packed together tight Liquids – particles are less densely packed than a solid Gas – weak energy, particles move freely. 24. How is a solid changed to a liquid? By melting- adding thermal energy 25. Define evaporation and condensation. Condensation – when gas vapors cool and become liquid. Evaporation – liquid heats up and becomes gas.

14. 26. What is a physical property of matter? Physical property is a characteristic that can be observed without changing the identity of a substance. Name those in your text. Ex: Mass, color, volume, hardness, and magnetism What is a chemical property? Chemical property is a characteristic that describes how a substance will interact during a chemical reaction. New substances are formed. Give examples. Ex: reactivity – ability to burn, rust, react to light, react with acids.

15. 27. What is the pH scale? The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic.

16. 28. What is a physical change and chemical change? Physical Change – alters the physical properties of a substance without changing the identity of the substance. Ex: melting ice or evaporation Chemical change – substance changed into a new substance with different properties Ex. sugar, eggs, and flour create a batter. Baking the cake batter creates a cake. 29. How would you describe a match being lit and a nail rusting? Chemical changes: -a match being lit: combustion (burning) -nail rusting: oxidation (rust)- Iron reacts with oxygen

17. 30. What is the difference between the Kelvin and Celsius scale? Degrees: Increase/decrease by the same amount. Celsius has negative degrees. Kelvin is usually used to measures extreme temperatures like its lowest: absolute zero (theoretical: motionless particles). • Explain how a hydroelectric plant (dam) turns potential energy into electrical energy. The water has gravitational potential energy due to its position (height). As it falls, it changes into kinetic energy because of its motion. As the water moves the turbines, it is mechanical energy. A generator transforms this work into electrical energy. potential kinetic mechanical electrical

18. 32. Hot chocolate and ice water are placed inside a container. What will eventually happen to the temperature of the hot chocolate and ice water? The hot chocolate will lose heat and the ice water will gain heat until the temperatures are equal. 33. A girl is swinging back and forth on a swing set. She swings forward at her highest point and is about to jump off. What type of energy does she have? She has potential energy at the highest point on the swing. Remember: objects have the greatest potential energy when they are at the greatest height. • A humpback whale is leaping out of the water. Explain what type of energy the whale has as he leaps out of the water. Kinetic energy, but as it gains height potential.

19. A man lifts a heavy bucket by pulling upward on the handle. As the man pulls on the handle and lifts the bucket what kind of energy is being applied to the bucket? Mechanical energy • Explain the transformation of energy taking place as a car burns up gasoline. The gasoline burning is chemical energy. Chemical energy is turned to mechanical energy as the car moves. Some is as changed to thermal energy. • Define conduction and convection and give an example of each. Conduction – is the transfer of heat by direct contact of particles. Example: Heating a pan on the stove. Convection – when heat is transferred in fluids or gases by currents moving in a circular motion. Example: water heating up on the stove.

20. Define and give an example of chemical energy, nuclear energy, mechanical energy, thermal energy, electromagnetic energy, and electrical energy. Chemical energy – energy stored in chemical bonds. Examples: The flame of a candle or digesting food Nuclear energy – energy stored in the nucleus of an atom as a result of the nuclear forces. Examples: Nuclear power plant (fission). Stars burning (fusion)  Mechanical energy – the sum of an object’s potential and kinetic energy Example: throwing a ball in the air. Thermal energy – the total amount of energy of an object due to the motion of the particles. Example: a cup of hot chocolate. Electromagnetic energy – travels in waves. It has some electrical and magnetic properties Example: X-rays, light. Electrical energy – the energy of moving charges (electrons). Example: Most of our appliances/electronics use electrical energy: toasters, lights, televisions, etc.

21. 39. Describe the Law of Conservation of Energy. Energy changes form, but is never created or destroyed. 40. Describe electromagnetic waves. What are the 7 major parts of electromagnetic waves? Electromagnetic waves do not require a medium in which to travel. Radio, microwave, infrared, visible light, ultraviolet, x-ray, and gamma rays. 41. Describe mechanical waves. Requires a medium in which to travel. 42. What makes electromagnetic and mechanical waves different? Mechanical waves use only matter for travel and electromagnetic use matter and space for travel.

22. 43. Draw a transverse wave and diagram the following parts: amplitude, wavelength, crest, and trough. Define each part of the wave. Amplitude – a measure of how high crests are; the greater the amplitude, the more energy a wave carries Wavelength—distance from the top of one crest to the top of the next crest or from the bottom of one trough to the bottom of the next trough Crest – highest part of wave Trough – lowest part of wave

23. 44. Draw a longitudinal wave and diagram the following parts: rarefaction & compression.