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SCIENCE Baseline Assessment Grade 11. Questions 1-15. SC. A-1.4.3 PHASE CHANGE gain or loss of energy (Questions 1-2-3). GAIN ENERGY. (+) energy gain (-) energy loss. (Questions 4-5-6). SC. A-1.4.4 RATES of REACTION- depend on temperature, pressure, concentration of reactants,
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SCIENCEBaseline AssessmentGrade11 Questions 1-15
SC. A-1.4.3 PHASE CHANGEgain or loss of energy(Questions 1-2-3) GAIN ENERGY
(Questions 4-5-6) • SC. A-1.4.4 RATES of REACTION-depend on • temperature, • pressure, • concentration of reactants, • presence or absence of catalysts
Temperature of reactants ….as you increase the temperature the rate of reaction increases.
Pressure of reactants • Increasing the pressure on a reaction involving reacting gasesincreases the rate of reaction. • Changing the pressure on a reaction which involves only solids or liquids has NO effect on the rate.
Concentration of reactants (It’s complicated!) • For many reactions involving liquids or gases, increasing the concentration of the reactants increases the rate of reaction. • In a few cases, increasing the concentration of one of the reactants may have little noticeable effect of the rate. These cases are discussed and explained further down this page. • Don't assume that if you double the concentration of one of the reactants that you will double the rate of the reaction. It may happen like that, but the relationship may well be more complicated.
Presence or absence of catalysts • Catalyst present, increases rate of reaction • By lowering the activation energy require for the reaction to occur.
Catalyst- substance that increases the rate of reaction by lowering the activation-energy barrier (the catalyst is not used up in the reaction.)Inhibitor-slows the rate of reaction, can stop reaction completely.
Activation Energy-theminimum energy colliding particles must have in order to react The spark is the catalyst and lowers the activation energy required for the reaction to happen!
Catalysts may reduce the amount of activation energy required for a chemical reaction to occur. Platinum (Pt) is a catalyst that is used in catalytic converters in automobiles. In the graphs below, pathway x is a solid line representing the uncatalyzed reaction. The dotted line shows the catalyzed reaction. Which graph best illustrates the changes in a reaction when the catalyst reduces the amount of energy required? A. B. Products Products Products Products Reactants Reactants Reactants Reactants Potential Energy /PE Potential Energy /PE Potential Energy /PE Potential Energy /PE x x x x C. D. Reaction Rate → Reaction Rate → Reaction Rate → Reaction Rate → Correct answer-D.Activation Energy lowered. Products generated are not increased or decreased.
The periodic table is arranged by atomic number(the number ofprotons in an element). • Eachcolumn of elements from the top to the bottom is called agroup (also family).Groups of elements have properties that are alike. All the elements in a group have the same number of electrons in their atoms' outer shells. Each group has a letter and a number. All of the elements inGroup 1 have one electron in their atoms' outermost shell (valence shell). • The elements going across (row) on the table are called periods. Each period has a number. The elements in a period have different properties. All elements in the left-hand side of a period tend to lose electrons and become positively (+) charged. The atoms of the elements toward the right side of the period tend to gain electrons. These elements become negatively (-) charged. All the atoms at the far right neither gain nor lose electrons. They are stable elements. These are called Noble Gases (Inert Gases).
SC.B.1.4.1ENERGYEnergy required for biological processes, building, erosion, rebuilding of Earth. Energy is defined as the capacity to do work. An object has kinetic energy if it is moving. If there are some constrained or pent-up forces, preventing the object to move, the object is said to have potential energy. There are various subsets or forms of both kinetic and potential energy, such as: heat, chemical, electrical, light and nuclear energy.
Kinetic energy (KE)-energy that an object or particle has because it is moving • Potential energy (PE)-stored energy that an object has because of its position or shape • Thermalenergy (Heat energy)-total KE contained in all particles of a substance.
Heat energy • Heat is the movement of molecules. It is the sum of the kinetic energy of an object's molecules. • Electrical energy • Electrical energy is the movement of electrons. That is kinetic energy. The voltage in an electrical circuit is the potential energy that can start electrons moving. Electrical forces cause the movement to occur. • Chemical energy • Chemical energy is potential energy until the chemical reaction puts atoms and molecules in motion. Heat energy (KE) is often the result of a chemical reaction. • Light energy • Light is the movement of waves and/or light particles (photons). It is usually formed when atoms gain so much kinetic energy from being heated that they give off radiation. This is often from electrons jumping orbits and emitting moving photons. • Nuclear energy • Certain elements have potential nuclear energy, such that there are internal forces pent up on their nucleus. When that potential energy is released, the result is kinetic energy in the form of rapidly moving particles, heat and radiation.
1) Clara carries a glass of ice water outside on a hot day. She sets it down and rushes inside to answer the phone. When she returns, the ice has melted. What is the best explanation for what happened to the drink? A. The warm air carried convection heat currents, which melted the ice molecules. B. The ice molecules passed their cold energy to the water molecules, resulting in the liquid state. C. The ultraviolet rays from the Sun heated the ice molecules, decreasing their kinetic energy and increasing their attraction. D. The ice molecules absorbed energy from their surroundings, gained kinetic energy, and overcame the forces holding them in a solid phase.
2.For most substances, freezing and melting occur at the same temperature. Which of the following best explains the difference between the processes of melting and freezing? A. When a substance melts, its molecules are slowing down; when freezing, its molecules are speeding up. B. When a substance freezes, its molecules move farther apart; when melting, its molecules come closer together. C. When a substance melts, its molecules have a decrease in kinetic energy; when freezing, its molecules have an increase in kinetic energy. D. When a substance freezes, its molecules release energy; when melting, its molecules require an input of energy to change it to a liquid.
3. Mica is sweating after winning his 1OO-meter race. Which best explains why sweating helps Mica cool off? A. The liquid sweat evaporates, which takes heat energy from his body. B. The liquid sweat allows conduction of heat from his body to the air. C. The sweat allows heat to escape by increasing wind chill, making his body feel colder. D. The sweat forms on his skin and allows his body to adjust its temperature by convection.
4. Bobby is planning to cook some hot dogs using a charcoal grill. After he lights the charcoal, it burns very slowly. Bobby's brother suggests blowing on the charcoal to make it burn faster. Which of the following explains why his brother's suggestion works? A. Blowing on the charcoal decreases the temperature of the charcoal. • Blowing on the charcoal catalyzes the reaction that causes • the charcoal to burn. C. Blowing on the charcoal increases the concentration of oxygen at its surface. D. Blowing on the charcoal reduces the amount of energy needed for the charcoal to burn.
5. Oxygen gas (O2) and potassium chloride (KCl) can be produced in the laboratory by heating solid potassium chlorate (KCIO:), as shown by the following chemical reaction:2KClO3(s) 2KCl(s) + 3O2 (g)Even with heating, the reaction is rather slow, but it can be sped up by mixing in some manganese dioxide (MnO2). T he MnO2 can’t re recovered unchanged after the reaction. How is MnO2 acting to increase the reaction rate? A. MnO2 is a catalyst for the reaction. B. MnO2 adds energy to the reaction. C. MnO2 decreases the concentration of KClO3. D. MnO2 provides more oxygen to the reaction.
6. Iron (Fe) is an important catalyst used in the commercial production of ammonia (NH3). Which of the following best describes why iron is used in the reaction to produce ammonia? A. The iron becomes part of the ammonia product. B. The iron helps yield higher-quality ammonia. C. The iron lowers the activation energy needed to produce ammonia. D. The iron speeds up the production of ammonia by increasing the temperature.
7. Sean is studying the periodic table of elements. What do elements in the same group in the periodic table have in common? A. energy levels B. ionization energy C. number of protons D. number of valence electrons
8. Newlands, Meyer, Mendeleev, and Moseley made contributions to the modem periodic table of elements.The Periodic Law that exists in the modern periodic table states that elements show periodic repetition oftheir physical and chemical properties when arranged by a particular property. Elements in the modernperiodic table are arranged by increasing: A. atomic mass. B. atomic number. C. atomic radius. D. ionization energy.
9. lonization energy is the energy needed !o remove an electron from an atom. The graph below shows the ionization energy for the first 20 elements of the periodic table. Which best explains why the noble gases: Helium (He), Neon (Ne), and Argon (Ar) have the highest ionization energies? A. They all have the same electron configuration. B. They all have a full set of valence electrons. C. They all are very reactive when added to acidic solutions. D. They all chemically bond with the alkali metals to form ionic compounds.
Household appliances operate by converting energy from one form to another. For example, microwave ovens convert energy in order to cook food. Which statement correctly identifies the kind of energy used by microwave ovens and how it cooks food? • A. Kinetic energy is used to produce solar radiation which cooks the food. • Nuclear energy is used to produce potential energy • which cooks the food. • C. Heat energy is used to produce mechanical energy which cooks the food. • D. Electric energy is used to produce electromagnetic radiation which cooks the food.
11. Because nonrenewable resources are in limited supply, the development of alternative energy resources is becoming increasingly important. Which of these describes an energy conversion that occurs when a renewable energy resource is used? A. Kinetic energy is converted to radiant energy as light strikes a solar panel. B. Potential energy is converted to mechanical energy in a hydroelectric dam. C. Nuclear energy is converted to potential energy during a fission reaction. D. Chemical energy is converted to electric energy through the burning of fossil fuels.
12. Kelly is building a model of a volcano. Her plan involves combining baking soda and vinegar to simulate the eruption of the volcano. She tests the reaction in a glass beaker first. When a small amount of baking soda and vinegar combine, carbon dioxide is produced, along with some foam and fizz inside the beaker. How do the beaker's contents after reaction compare to the contents before reaction? • A. The mass inside the beaker decreases as carbon dioxide gas leaves the beaker. • B. The mass inside the beaker changes, depending on the type of beaker used. • C. The mass inside the beaker increases, since the products are more dense than the reactants. • D. The mass inside the beaker stays the same because the total amount of mass can never change.
EXTRA ENERGY QUESTION: All organisms on Earth need food to live and grow. These organisms either produce their own food, via photosynthesis, or eat other organisms according to complex food webs. The energy that is transferred through these processes can be traced back to what feature of our universe? • A. the Sun • B. distant planets • C. the water on Earth • D. geothermal atmosphere EXTRA ENERGY QUESTION: In order to do work, energy needs to be converted from one form to a more useful form for the particular task. When someone hammers a nail into a piece of wood, energy is converted from gravitational potential energy to which more useful form? • A. electromagnetic energy • B. kinetic energy • C. sound energy • D. thermal energy