Unit 1: Nature of Science

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1 Name pd. DUE:. 8 th Grade Science Review: Directions: Use your class notes, GOOGLE, and/or the textbook to answer the questions below: Unit 1: Nature of Science Read the scenario below then answer the following questions: A scientist observes that the percent of fish eggs that seem to hatch is affected by the temperature of the water in an aquarium. She is attempting to identify which water temperature will cause the highest percentage of fish eggs to hatch. In the wild, the fish normally live in a lake where temperatures are around 25 C. The scientist sets up 5 aquariums at the following temperatures: 5 C, 15 C, 25 C, 35 C, and 45 C. She adds 50 fish eggs to each aquarium and, after 10 days, records the total number of eggs that hatch in each aquarium to get the % hatch rate per tank. 1. Write a possible hypothesis for this experiment using and if/then statement: 2. Which group of fish would be the control group? Why? Explain what a control group is: 3. What is the independent variable? 4. What is the dependent variable? 5. What would be at least 4 constants you would have in this experiment? 6. The scientist is only doing trial at each level because they are calculating ONE % hatch rate per tank. To make the results more reliable, she should the experiment several more times. How/why does doing this make results more reliable? Explain: 7. What type of graph would you make to best represent this data? Why?

Unit 2: Measuring and Describing Matter 1. We can describe matter in terms of its physical and chemical properties. **Textbook pages: 44, 50 a. What is a physical property of matter? b.

**Textbook pages: 44-47, 50 PHYSICAL PROPERTY OF MATTER CHEMICAL PROPERTY OF MATTER State of Matter at room temperature Boiling/Condensation points Melting/Freezing points Weight Flammability

**Textbook pages: 45-47 3b. What is the density of the marble? Show your work: Formula Set-up w/units Answer w/units 4. Do the following conversions: 1200 mg = g 14km = m 109 g = kg 5.

2 Unit 2: Measuring and Describing Matter 1. We can describe matter in terms of its physical and chemical properties. **Textbook pages: 44, 50 a. What is a physical property of matter? b. A chemical property of matter? 2. Indicate if a property is physical or a chemical property of a substance by drawing an arrow from the property to the words physical or chemical properties. **Textbook pages: 44-47, 50 PHYSICAL PROPERTY OF MATTER CHEMICAL PROPERTY OF MATTER State of Matter at room temperature Boiling/Condensation points Melting/Freezing points Weight Flammability Mass Volume Reactivity Density Length Solubility Color Texture 3a. In the pictures above, a student uses a triple beam to find the mass of a marble and a to find its. **Textbook pages: b. What is the density of the marble? Show your work: Formula Set-up w/units Answer w/units 4. Do the following conversions: 1200 mg = g 14km = m 109 g = kg 5. In the phase change graphs below, highlight where a PHASE CHANGE is happening: *Textbook pgs: 79 How do you know this is where a phase change is taking place based on the graph? What happens to temperature during a phase change?

UNIT 3: Atoms and the Periodic Table: 1. Label the main parts of the atom below: *Textbook pgs: 319 A: D: B: E: C: 2) An atom s mass number = # + #.

*Textbook pgs: 342 PERIOD: GROUP: 4) Most of the elements on the periodic table are (what type of elements) *Textbook pgs: 340 5) Match and name the theorist with the model

Thomson:, model name: d) Rutherford:, model name: e) Bohr:, model name: f) Heisenberg and Schrodinger:, Model name: electron cloud mode (statistical model of electron

3 UNIT 3: Atoms and the Periodic Table: 1. Label the main parts of the atom below: *Textbook pgs: 319 A: D: B: E: C: 2) An atom s mass number = # + #. *Textbook pgs: 322 3) What is a period and a group on the periodic table? *Textbook pgs: 342 PERIOD: GROUP: 4) Most of the elements on the periodic table are (what type of elements) *Textbook pgs: 340 5) Match and name the theorist with the model *Textbook pgs: a) Democritus-atomos-atoms are particles that can t be divided b) Dalton- atoms bond with other atoms in specific ratios to form different substances c) Thomson:, model name: d) Rutherford:, model name: e) Bohr:, model name: f) Heisenberg and Schrodinger:, Model name: electron cloud mode (statistical model of electron placement/probability) 6) Fill in the chart. You should not need a periodic table! element square OR isotope notation Atomic # (p.321) Atomic Mass (p.323-in-text definition) Mass # (or mass # of most commonly occurring natural isotope) Carbon Carbon-12 # of protons # of electrons # of neutrons Sodium Zinc-63

Instead of having an equal number of protons and electrons, the atom now has less electrons, so its overall charge is A negative ion is formed when an atom one, two, or three Valence Electrons from

4 Unit 4: Bonding and Classifying matter: 1) How does an atom become a positive ion? A negative ion? *Textbook pgs: A positive ion is formed when an atom one, two, or three of its Valence Electrons in order to achieve a full shell of Valence Electrons. Instead of having an equal number of protons and electrons, the atom now has less electrons, so its overall charge is A negative ion is formed when an atom one, two, or three Valence Electrons from another atom in order to achieve a full shell of Valence Electrons. Instead of having an equal number of protons and electrons, the atom now has more electrons, so its overall charge is 2) In a covalent bond, valence electrons are. Covalent bonds are between elements only. *Textbook pg: 372 In an ionic bond, valence electrons are or. Ionic bonds are between a and a *Textbook pg: 371: 3) Classify the following compounds as either IONIC or COVALENT: (use info above) H 2O : bond NaCl : bond C 6H 12O 6: bond 4i-vi: Use the particle-level depictions to the right. *Textbook pg: 90, 94, 98: i) Which picture(s) represent(s) a PURE SUBSTANCE? ii) Which picture(s) represent(s) a MIXTURE? iii) Which picture(s) represent(s) a HOMOGENEOUS MIXTURE? iv) Which picture(s) represent(s) a HETEROGENEOUS MIXTURE? v) Which picture(s) represent(s) a PURE ELEMENT? vi) Which picture(s) represent(s) a PURE COMPOUND? UNIT 5: Chemical reactions, Acids and Bases 1) In a chemical reaction (chemical change), substances are formed that have and different properties. *Textbook pg: 52: 2) In a chemical reaction (chemical change), atoms in the original substances get and form new bonds with other atoms. In a physical change, no rearranging of atoms takes place. The chemical structure of the substances remains the. *Textbook pg: 390 (not exact wording):

3) Classify the following as describing a chemical change OR a physical change in matter: Draw an arrow from the description statement to the type of change it is describing: *Textbook pg: 48-49,

5 3) Classify the following as describing a chemical change OR a physical change in matter: Draw an arrow from the description statement to the type of change it is describing: *Textbook pg: 48-49, 52-53: PHYSICAL CHANGE (chemical structure is NOT changed) CHEMICAL CHANGE (changes to chemical structure new substances formed) Boiling water An iron nail rusting (reacting with oxygen) Roasting and burning a marshmallow Ice forming in the freezer Crushing a piece of paper Water evaporating from a bird bath Air temperature going from A bright yellow precipitate forming when lead nitrate and potassium iodide are put together. Moving your notebook 2 cm. Mixing oil and water. Making a salad. 4) In five molecules of silver bromate, chemical formula 5AgBrO3, there are a total of *Textbook pg: 396, 392 Ag atoms, Br atoms, and O atoms 5) In 3 molecules of cobalt molybdate, chemical formula 3CoMoO4, there are a total of *Textbook pg: 396, 392 Co atoms, Mo atoms, and O atoms 6) Fill in the missing information in the picture to the right according to the Law of Conservation of Mass: *Textbook pg: 395 7) Tell if the following chemical equations are already balanced show how you know. If they are not balanced, show your work and add co-efficients to balance them!! Blanks may or may not need numbers. *Textbook pg: 396 a) Fe + O 2 Fe 2O 3 b) Mg + N 2 Mg 3N 2 8) fill in the empty boxes/blanks on the ph scale diagram below: *Textbook pgs: 429,

6 UNIT 6: Motion, Force, and Newton s Laws: 1) Tell what is being represented by each graph below: *Textbook pg: textbook does not do a very good job with this use your unit 6 notes, or google motion graphs for more help!!! A) 1. The slope (steepness) of line = ZERO (0) (constantly) CONSTANT (something over 0) INCREASING (getting steeper) DECREASING (getting less steep) 2. the y axis of this graph is 3. Therefore, this graph represents an object that has Constant or NO (B) 1. The slope (steepness) of line = ZERO (0) (constantly) CONSTANT (something over 0) INCREASING (getting steeper) DECREASING (getting less steep) 2. the y axis of this graph is. Meaning, for each unit of time, the object is changing the same amount of. 3. Therefore, this graph represents an object that has Constant or NO C) 1. The slope (steepness) of line = ZERO (0) (constantly) CONSTANT (something over 0) INCREASING (getting steeper) DECREASING (getting less steep) 2. the y axis of this graph is 3. Therefore, this graph represents an object that has Constant or is NOT (D) 1. The slope (steepness) of line = ZERO (0) (constantly) CONSTANT (something over 0) INCREASING (getting steeper) DECREASING (getting less steep) 2. the y axis of this graph is Meaning, for each unit of time, the object is increasing the amount of it s covering. 3. Therefore, this graph represents an object that has Constant or is up 2) NEWTON S LAWS OF MOTION: a) FIRST LAW: *Textbook pg: 158 Objects in motion will at a constant, and objects at will stay at until acted upon by an force. You kick a soccer ball into an open field. To start it in motion, you had to exert an force on the ball. Once the ball is in motion, it will stay in motion at the same and in the same that you kicked it. However, it will not keep moving this way forever, because the force of acts against it, slowing the motion of the ball down until it stops.

7 b) SECOND LAW: *Textbook pg: 161 Acceleration of an object depends on the exerted on it and the of the object. A 2kg and 15 kg toy cars were each pushed with a 3N force and a 10N force. Which combination produced the highest acceleration? Show your calculations below (F= ma, so A=F/m) *Textbook pg: 162 2kg toy car with 3 N force (low mass, low force) 2kg toy car with 10 N force ( low mass, high force) FORMULA SET-UP ANSWER (acceleration =) FORMULA SET-UP ANSWER (acceleration =) 15kg toy car with 3 N force (higher mass, low force) 15 kg toy car with 10 N force (higher mass, higher force) FORMULA SET-UP ANSWER (acceleration =) FORMULA SET-UP ANSWER (acceleration =) c) THIRD LAW: *Textbook pg: 163 For every action force exerted, there is an and reaction force exerted back on the original object/body. o The man below exerts 50N on the wall, and the wall exerts 50N back on him. Why isn t he moving backwards? (the force of under his feet exerts an equal and opposite force on the man, causing him not to move) o Draw a situation where the man would move back: UNIT 7: WORK AND POWER: 1. Work is done when an object is through a distance in the same as the applied force. *Textbook pg: A machine makes work easier by changing the and/or the of the force. When using a machine, although it may seem easier, you will actually end up doing work than if no machine was used, due to the force of. *Textbook pg: Power is the at which work is done. *Textbook pg: You lift a 400N box straight up 2m high. It takes you 8 seconds. How much work (in joules) and how much power (in J/s or Watts) did you do on the box? (W=Fd, P=W/t) WORK: FORMULA SET-UP ANSWER (work=) POWER: FORMULA SET-UP ANSWER (work=)

8 UNIT 8: ENERGY: 1) No energy can be or. *Textbook pg: 255 However, it can be converted into different forms. Whenever one form of energy is converted into another form of energy, some of the original energy is always converted into energy (due to friction). *Textbook pg: 255 2) In the energy transformations web below, fill-in the missing energy types: *Textbook pg: 246,244, 3) You drop a pendulum weight at point 1 in the diagram to the right. At which point or points does the pendulum have the most notes what affects the amount of PE vs. KE? Gravitational Potential energy in a FRICTIONLESS environment?. Gravitational Potential energy In a REALISTIC environment? Kinetic Energy? Why would it have the most KE here?

UNIT 9: WAVES 1) WAVE INTERACTIONS: each picture/diagram below represents either,, or.

*Textbook pgs: 584, 585, 586 a) This picture best b) This picture best c) This picture

go through completely empty space are known as: waves.

bottom) 4) SOUND waves are examples of waves.

: (a) water (b) air (c) metal (d) a vacuum 5) Wavelength and Frequency have an

*Textbook pg: 583 A wave with a HIGH FREQUENCY will have a wavelength To the right, draw

9 UNIT 9: WAVES 1) WAVE INTERACTIONS: each picture/diagram below represents either,, or. Circle the choice that is best represented by each picture/diagram. *Textbook pgs: 584, 585, 586 a) This picture best b) This picture best c) This picture best e) This picture best d) These pictures best f) This picture best 2) Waves that CAN go through completely empty space are known as: waves. *Textbook pg: 576 (italicized) 3) Waves that CANNOT go through completely empty space are known as: waves. *Textbook pg: 575 (italicized near bottom) 4) SOUND waves are examples of waves. *Textbook pg: 575 Which of the following can sound NOT pass through? : (a) water (b) air (c) metal (d) a vacuum 5) Wavelength and Frequency have an relationship. *Textbook pg: 583 A wave with a HIGH FREQUENCY will have a wavelength To the right, draw an example of a wave with HIGH frequency: A wave with a LOW FREQUENCY will have a wavelength. To the right, draw an example of a wave with HIGH frequency: 6) Amplitude of a wave is the distance from rest position to the OR of a wave. *Textbook pg: 580 In the picture to the right, circle the wave with the HIGHEST AMPLITUDE: 7) The highest energy waves have a HIGH and a HIGH (and short ). *Textbook pg: 580, 581, 582

10 You are going to do great on the science SOL! You are prepared and ready to show off your science knowledge! If you come to a challenging question, just remember to think, take your time, and DO YOUR BEST!!!! You are ready for this!! HG Love, GS

Unit 2: Essentials of Chemistry Homework Packet (80 points)

Name: KEY Period: By the end of Unit 2, you should be able to: Essentials of Chemistry Chapter 1-2 & 4-5 Unit 2: Essentials of Chemistry 8. Explain the nature of science including the use of the validity