NAME ______PERIOD ______DATE ______
FINAL EXAM REVIEW
1. A student designed an experiment to study how temperature affects the rate at which enzymes digest protein. She put equal masses of liver into four equal-sized test tubes, brought the test tubes to different temperatures, introduced equal amounts of enzyme into each tube and measured the duration of the chemical reaction. What factors were held constant in the experiment? Constants are things that stay constant or the same through every trial of an experiment. For this experiment they are: Mass of liver, test tube size, & amounts of enzyme.
2. A student hypothesized that robins prefer large bird houses to small ones. He built four bird houses of different sizes to test his hypothesis. What was the independent variable in the student’s study? The independent variable is the cause in an experiment, the dependent variable is the effect of the experiment. The cause or the factor that is intentionally changed is the size of the bird house. The effect or what changed in the experiment is the number of birds at each house.
Base your answers to the following questions on the information and diagrams below.
Saltwater plants of the same species were grown in soil in separate containers with 1 liter of water. All of the plants were the same height at the beginning of the experiment. Different amounts of salt were dissolved in each container as shown in the diagrams. All other conditions were held constant. Measurements for the final height of each plant are provided.
3. What is the problem or testable statement for this experiment? The problem is the question the experiment tries to answer. In this experiment different amounts of salt were dissolved in water, and the plant growth was measured. The question would have to be something like: Does the amount of salt dissolved in water affect the growth of a saltwater plant.
4. Write a possible hypothesis for this experiment. The hypothesis is a testable statement, NOT A QUESTION! It is a prediction as to what will happen, NOT A QUESTION AS TO WHAT WILL HAPPEN! The hypothesis should be something like this: As more salt is dissolved in water, it will make the plants grow faster. The independent and dependent variables are always contained within the hypothesis.
5. What is the dependent variable for this experiment? The independent variable is the cause in an experiment, and the dependent variable is the effect. The independent (cause) is the amount of salt, and the dependent (effect) is the growth of the plant.
6. What is the control for this experiment? A control is the trial or group in the experiment that gets the least or no treatment from the independent variable. It is the one that doesn’t get any special treatment. In this experiment the amount of salt dissolved in water is the independent variable. The group that gets the least salt is the control and that is the container with no salt.
7. Define atom. The smallest unit of an element consisting of a nucleus made of protons and neutrons and an electron cloud that surrounds the nucleus.
8. What is the difference between an element, a compound and a mixture? Give an example of
each.
An element is a substance that consists of only one type of atom. (iron (Fe), hydrogen(H), calcium(Ca), cobalt(Co), etc.)
A compound is when two or more elements are chemically combined. This means they cannot be separated by anything other than a chemical reaction. A chemical reaction means that the substances you have at the end of the reaction are different from the substances you started with. (carbon dioxide(CO2, water(H2O), salt(NaCl), etc.)
A mixture is when 2 or more substances are combined, but they do not change the original substances. They can be sorted, filtered, or otherwise be separated by physical means. (Raisin bran, rocky road ice cream, salt water, cool aide, trail mix, etc.)
USE THE PERIODIC TABLE TO ANSWER QUESTION #9
9. Which element has 13 protons, 14 neutrons and 13 electrons? When identifying an element the only number that matters is the atomic number. The element with 13 protons, or the atomic number 13, is Aluminum.
10. Given a periodic table:
How do you find the number of protons in an element? Equals the atomic #
How do you find the number of neutrons? The number of neutrons equals the atomic mass minus the atomic number. The atomic mass is the average number of the total number of protons and neutrons in the nucleus. The atomic number is the number of protons, so by subtracting them from the total will leave you with the number of neutrons.
How do you find the number of electrons? The number of electrons is equal to the atomic number. When the number of electrons is different than the atomic number it is called an ion. Ions can be positive or negative depending if the atom gains or loses an electron. On this exam the questions do not involve ions, so the number of electrons will equal the atomic number.
__(ml) milliliter 11. The unit used to express liquid volume.
______(m) meter______12. The unit used to express length.
______(g/mL) grams per milliliter___13. The unit used to express density.
______(g) grams______14. The unit used to express mass.
15. Which instrument is used to calculate:
_balance______Mass of an object
__graduated cylinder______Volume of a liquid
_meter stick/ruler______Length of an object
16. Liquid displacement (water displacement) is how to find the volume of an irregularly-
shaped object. (Hint: putting it in a graduated cylinder and measuring the difference.)
17. Find the volume of the object using the graduated cylinders below.
Final Volume = ___49mL_
Initial volume = __33mL__
Volume of object = _16mL____
18. Using the picture, the mass of the object is ___30 g__
19. Given the mass from Q. #17 and the volume of the object from Q. #16, what is the density of the object? (D = M/V) _____1.875 g/mL_____
30g/16mL = 1.875 g/mL
20. Compare and contrast the 3 states of matter. Include information about each one’s shape,
volume, the arrangement and motion of particles.
Solid: have definite shape, particles have the least amount of energy (heat), vibrating the slowest, magnetic attraction between the particles is the greatest bringing them closer together, volume is typically the smallest.
Liquid: no definite shape, will take the shape of the container, particles have more energy (heat)than in the solid state at the same pressure, magnetic attraction between the particles is weak enough to allow particles to change places and flow but not weak enough to totally break free, volume is usually between solid & gas.
Gas: no definite shape, will fill entire volume of container, particles have the most energy (heat), attraction between particles is too weak to keep them close together and are able to move freely.
21. Convert 2.37 grams to:
kilograms _0.00237kg__ centigrams __237cg__ milligrams ____2370 mg__
22. Below are examples of physical and chemical changes. Place a Letter P next to the physical
changes, and a Letter C next to the chemical changes. A physical change is a change in size, shape, or state. It is still the same substance. If you carve a sculpture out of wood, it is still wood. A melted ice cube is still water. A chemical change leaves you with a different substance than you started with. Sodium(Na) + Chlorine(Cl)= salt- sodium chloride(NaCl) Burnt wood is no longer wood, it is ash.
___C__ rusting metal ___P__ripping paper __C__burning wood __P__water freezing
___P__ salt dissolving in water ___C__ mixing 2 liquids and a gas evolves.
23. Define conduction, convection, radiation and give an example of each.
Conduction: heat transfer through direct contact- objects must be touching each other. Vibrating molecules bump into each other transferring energy. Ex: When an ice cube melts in your hand.
Radiation: heat transfer through empty space by electromagnetic waves. Molecules absorb the electromagnetic waves, gain energy, vibrate faster. Ex: The ground warmed by the Sun.
Convection: heat transfer in a fluid. (liquid or gas) As a fluid is heated, it becomes less dense as the particles spread out. As they spread out they become less dense and rise. Cooler material is more dense and falls. The fallen material is then heated and rises. As it rises it cools. The process keeps repeating and convection currents are the result. Ex: Air warmed at the Earth’s surface, rises, cools, and falls causing areas of high and low pressure. Movement of the asthenosphere in the mantle, heated material rises then cools and sinks, pushing on the crust causing the Earth’s plates to move.
24. Using a colored pen/pencil, draw arrows to show how smoke would
move if a lit punk was placed in tube A. Travel down A, and up B.
25. Why does the air flow in this direction?
Heated less dense air over the candle causes low pressure, cooler more dense air over the ice creates high pressure. Air moves from high pressure to low pressure.
A B
25. Define: renewable resource – A resource that is constantly being replenished, or has an unlimited supply. Ex: Solar, wind, geothermal, etc.
non-renewable resource – A resource that cannot be replaced with in a lifetime. Ex: fossil fuels, coal, oil, etc.
26. How are rocks and minerals similar? How are they different? Minerals are a naturally occurring inorganic solid with crystal structure and definite chemical composition. Most rocks are made from minerals, but can include other things as well, such as organic material from living things. All minerals samples can be classified as rocks, but not all rocks are minerals.
27. Define:
Igneous rock: rocks made from cooling melted or molten material.
Sedimentary rock: Rocks made from fragments of other rocks. The fragments can be broken of pieces or they can be dissolved in water.
Metamorphic rock: An existing rock that is changed through heat, pressure, and chemicals.
28. What is the relationship between cooling rate and crystal size in an igneous rock?
When an igneous rock cools slowly it has time to grow large crystals. As it slowly cools some minerals will turn solid before others. They will float around the rest of the melt accumulating together with other similar solid crystals growing larger and exhibiting a definite crystal shape. (ex: granite) When an igneous rock cools quickly its crystal grains are very small. They don’t have the time to grow large and are just locked into solid form with other random minerals that will not have a defined crystal shape.
29. Name and describe the 5 agents of physical weathering.
1) Temperature change- thermal expansion and compression crack rock
2) Pressure change- release of pressure causes rock to crack.
3) Animal action- the activity of animals wear rock down.
4) Abrasion- wind, water, & gravity acts on rocks as particles scrape against them in the wind, water or fall.
5) Plant growth- plant roots help crush and break up rock.
30. Number the following in order from the most permeable (#1) to the least permeable (#4). Permeability is how easy water can flow through the soil.
silt/mud __4__ coarse sand __2____ gravel ___1____ fine sand _3___
31. How are continental crust and oceanic crust different? How does this affect the outcome (features formed) when they collide? Continental crust is made of the less dense rock granite, and oceanic crust is made of the more dense rock basalt. The more dense rock will sink, or be subducted, under the continental crust. As that crust sinks it crumples the continental crust, and the oceanic crust starts to melt while bringing water in with it. This creates pockets of thick sticky magma with a lot of gases, which in turn creates a chain of volcanoes on the continent along that plate boundary.
32. How did scientists get information about the interior of the Earth? By studying seismic waves. By seeing how the seismic waves change, scientists can infer what the material it is traveling through is or what its properties are. Ex: P waves travel through all substances, S waves cannot travel through liquids or gases. The places on the Earth where S waves do not reach tells scientists that the outer core is liquid.
33. Describe the evidence Wegener used to support the Theory of Continental Drift. What
evidence was he lacking to help prove his theory? Wegener collected evidence from:
1) Fossils- fossils of the same species were found oceans apart with no way of traveling there.
2) Landforms- the continents seemed to fit together like a puzzle, mountains, plains, and coalfields on adjoining pieces matched when the puzzle was assembled.
3) Climate- glaciers in Africa and tropical fossils of plants on islands in the arctic circle indicate that their positions had changed.
*He could not provide a mechanism for how or why the continents were moving.
34. Define the three types of stress and identify the type of fault they create and which boundary they are associated with.
1. Tension: pulling apart, divergent boundary, normal fault- head wall moves down in relationship to the foot wall.
2. Compression: pushing together, convergent boundary, reverse fault- head wall moves up in relation to the footwall
3. Shearing: sliding past each other in opposite directions, transform boundary, strike slip fault- slipping past each other side by side
35. According to the theory of sea-floor spreading, where on the ocean floor are the youngest and oldest rocks found? New crust is created at the mid ocean ridge when molten material cools, as more crust is made the older crust is pushed aside. Therefore, young crust is found close to the ridge and old crust is further away.
36. If the difference in arrival times of the P and S waves is far apart, what is true about the distance to the epicenter? * Know how to read the chart on page 161 P and S waves and distance to epicenter.
P waves travel faster than s waves. Therefore the further the waves travel, the p wave will increase the distance between them. This causes the time elapsed between their arrivals to increase with distance.