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Science Object

Chemical Reactions: Matter and Energy in Reactions Grade Level: Elementary School, Middle School Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the final of four Science Objects in the Chemical Reactions SciPack. It explains how different configurations of atoms and molecules are associated with different energy levels. Some changes of configuration among atoms and molecules require a net input of energy whereas others cause...  [view full summary] Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the final of four Science Objects in the Chemical Reactions SciPack. It explains how different configurations of atoms and molecules are associated with different energy levels. Some changes of configuration among atoms and molecules require a net input of energy whereas others cause a net release. As a result, chemical reactions may release or consume energy. Some reactions such as the burning of fossil fuels release large amounts of energy by losing heat and by emitting light. Energy from light and other electromagnetic radiation can initiate many chemical reactions such as photosynthesis and the evolution of urban smog. The behavior of atoms in chemical reactions demonstrates the conservation of matter: When the number of atoms in a closed system stays the same, their total mass remains constant no matter how they are rearranged. [hide full abstract] Member Price: Free      Nonmember Price: Free

Science Object

Chemical Reactions: Rates of Chemical Reactions Grade Level: Elementary School, Middle School Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of four Science Objects in the Chemical Reactions SciPack. It demonstrates how chemical reactions can take place in time periods ranging from the few femto-seconds (10-15 seconds) required for an atom to move a fraction of a chemical bond distance to geologic time scales...  [view full summary] Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of four Science Objects in the Chemical Reactions SciPack. It demonstrates how chemical reactions can take place in time periods ranging from the few femto-seconds (10-15 seconds) required for an atom to move a fraction of a chemical bond distance to geologic time scales of billions of years. The rate of reactions among atoms and molecules depends on how often they encounter one another, which is affected by the concentration, pressure (for gases), and temperature of the reacting substances. The configuration of atoms in a molecule determines the molecule's properties. Shapes are particularly important in determining how large molecules interact with others. Some atoms and molecules called catalysts are highly effective in accelerating chemical reactions. Chemical reactions in living systems are catalyzed by protein molecules called enzymes. [hide full abstract] Member Price: Free      Nonmember Price: Free

Science Object

Electric and Magnetic Forces: Electrostatics and Current Electricity Grade Level: Elementary School, Middle School Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the second of three Science Objects in the Electric and Magnetic Forces SciPack. It explores the ability of electrons to flow, producing an electric current. Negative charges, being associated with electrons on the outer edges of atoms, are far more mobile in materials than...  [view full summary] Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the second of three Science Objects in the Electric and Magnetic Forces SciPack. It explores the ability of electrons to flow, producing an electric current. Negative charges, being associated with electrons on the outer edges of atoms, are far more mobile in materials than positive charges located in the nucleus at the center of an atom. In some materials, such as metals, electrons flow easily, whereas in insulating materials such as glass they can hardly flow at all. At very low temperatures, some materials become superconductors and offer no resistance to the flow of current. In between these extremes, semi-conducting materials differ greatly in how well they conduct, depending on their exact composition. Electric currents occur when charges move through conductors. Batteries and other devices store electrical energy by separating and concentrating charges. Electrical circuits provide a means of transferring electrical energy into other forms of energy such as heat, light, and sound. [hide full abstract] Member Price: Free      Nonmember Price: Free

Science Object

Gravity and Orbits: Gravitational Force Grade Level: Elementary School, Middle School, High School Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the second of three Science Objects in the Gravity and Orbits SciPack. It investigates the variables that influence gravitational forces acting on objects. Mass is a measure of the amount of matter that makes up an object (regardless of where that object is located) and weight is...  [view full summary] Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the second of three Science Objects in the Gravity and Orbits SciPack. It investigates the variables that influence gravitational forces acting on objects. Mass is a measure of the amount of matter that makes up an object (regardless of where that object is located) and weight is a measure of the gravitational force acting on an object. The strength of the gravitational force between masses is proportional to the product of the masses and inversely proportional to the square of the distance between them. Gravity will cause all objects at the same distance from Earth’s surface to fall toward Earth with the same acceleration regardless of their mass. [hide full abstract] Member Price: Free      Nonmember Price: Free

Science Object

Atomic Structure: Investigating Atoms Grade Level: Elementary School, Middle School, High School Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the first of three Science Objects in the Atomic Structure SciPack. It discusses the basics of atomic structure and how we know what we know about atoms. Atoms are made of a positive nucleus surrounded by negatively charged electrons. The nucleus is a tiny fraction of the volume...  [view full summary] Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the first of three Science Objects in the Atomic Structure SciPack. It discusses the basics of atomic structure and how we know what we know about atoms. Atoms are made of a positive nucleus surrounded by negatively charged electrons. The nucleus is a tiny fraction of the volume of an atom but makes up almost all of its mass. The nucleus is composed of protons and neutrons, which have roughly the same mass but differ in that protons are positively charged while neutrons have no electric charge. Isotopes of the same element have the same number of protons (and therefore of electrons) but differ in the number of neutrons. The electric force between the nucleus and electrons holds the atom together. [hide full abstract] Member Price: Free      Nonmember Price: Free

Science Object

Cells and Chemical Reactions: Basics of Metabolism Grade Level: Elementary School, Middle School, High School Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the first of four Science Objects in the Cells and Chemical Reactions SciPack. It investigates the basics of cellular metabolisms in plants and animals. Chemical reactions occur in all cells, are fundamental to cell functions, and are essential to maintain the chemical...  [view full summary] Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the first of four Science Objects in the Cells and Chemical Reactions SciPack. It investigates the basics of cellular metabolisms in plants and animals. Chemical reactions occur in all cells, are fundamental to cell functions, and are essential to maintain the chemical and physical organization of living systems. All living organisms engage in metabolic processes that take place inside their cells. Metabolism refers to all of the chemical activities and reactions in cells and organisms that are necessary for life. Metabolic processes can be categorized into two types, which are distinguished by their function in growth and maintenance of living cells: synthesis, chemical reactions that use energy to synthesize large and complex carbon-based molecules from smaller molecules; decomposition, chemical reactions that release energy from chemical bonds by decomposing the large molecules into smaller, simpler and lower-energy molecules. The energy released in decomposition is used to synthesize large molecules and in other cellular work, including: movement, maintenance and organization, transport of molecules, and transmission of nerve impulses. A large set of protein catalysts, called enzymes are required for both synthesis and decomposition chemical reactions. Because all matter tends toward disorganized states, constant input of energy is required by all cells to maintain chemical and physical organization. Without this organization, cells and organisms die, and with death (the cessation of energy input) living systems rapidly disintegrate. [hide full abstract] Member Price: Free      Nonmember Price: Free

Science Object

Atomic Structure: Energy in Atoms Grade Level: Elementary School, Middle School, High School Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of three Science Objects in the Atomic Structure SciPack. It investigates the forces at work within the nuclei of atoms and the energy contained in within atomic nuclei. Scientists continue to investigate atoms and have discovered even smaller constituents of which neutrons...  [view full summary] Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of three Science Objects in the Atomic Structure SciPack. It investigates the forces at work within the nuclei of atoms and the energy contained in within atomic nuclei. Scientists continue to investigate atoms and have discovered even smaller constituents of which neutrons and protons are made. The nuclear forces that hold the nucleus of an atom together, at nuclear distances, are almost always stronger than the electric forces that would make it fly apart. Nuclear reactions convert a fraction of the mass of interacting particles into energy, and they can release much greater amounts of energy than interactions between atoms. Fission is the splitting of a large nucleus into smaller pieces. Fusion is the joining of two nuclei at extremely high temperature and pressure, and is the process responsible for the energy of the sun and other stars. Energy is released whenever the nuclei of very heavy atoms, such as uranium or plutonium, split into middleweight ones, or when very light nuclei, such as those of hydrogen and helium, combine into heavier ones. [hide full abstract] Member Price: Free      Nonmember Price: Free

Science Object

Cells and Chemical Reactions: Cellular Respiration Grade Level: Elementary School, Middle School, High School Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of four Science Objects in the Cells and Chemical Reactions SciPack. It explores the process of cellular respiration in chemical reactions involved. Non-photosynthetic organisms obtain the energy necessary for cell growth and maintenance by decomposing large...  [view full summary] Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of four Science Objects in the Cells and Chemical Reactions SciPack. It explores the process of cellular respiration in chemical reactions involved. Non-photosynthetic organisms obtain the energy necessary for cell growth and maintenance by decomposing large molecules into smaller molecules that have lower energy levels stored in their chemical bonds (thus, releasing some energy from bonds so that it can be used to do cellular work). These smaller molecules can enter or exit the cell to be synthesized into larger complex molecules necessary for growth and maintenance of the organism. Organisms unable to photosynthesize, such as animals and fungi, must take matter into their cells to provide the building blocks (chemical constituents) and energy needed for metabolism (both synthesis and decomposition processes). The matter and energy that is stored in the structures that are synthesized by photosynthetic organisms (for example, the stems, roots and leaves of plants) can be consumed and used by other organisms as an essential source of this matter and energy. The chemical bonds in the molecules that are synthesized through photosynthesis and other synthesis processes contain energy that is needed by all cells (including plant cells). The energy stored in chemical bonds of the matter taken into the cells can be released and transferred into a form available for cellular work. This occurs when the bonds are broken through decomposition reactions and new compounds with lower energy bonds are formed. Cells capture some of the energy that is released during decomposition and usually store this energy temporarily in the phosphate bonds of a small high-energy compound called ATP. The energy stored in the bonds of ATP is then readily available for use by the cell for synthesis and other cellular work. [hide full abstract] Member Price: Free      Nonmember Price: Free

Science Object

Chemical Reactions: Categorizing Chemical Reactions Grade Level: Elementary School, Middle School Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the second of four Science Objects in the Chemical Reactions SciPack. It provides an understanding of the idea that a large number of important reactions involve the transfer of either electrons (oxidation/reduction reactions) or hydrogen ions (acid/base reactions) between reacting...  [view full summary] Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the second of four Science Objects in the Chemical Reactions SciPack. It provides an understanding of the idea that a large number of important reactions involve the transfer of either electrons (oxidation/reduction reactions) or hydrogen ions (acid/base reactions) between reacting ions, molecules, or atoms. In other reactions, chemical bonds are broken by heat or light to form very reactive radicals with electrons ready to form new bonds. Reactions involving these radicals control many processes such as the presence of ozone and greenhouse gases in the atmosphere, burning and processing of fossil fuels, the formation of polymers, and explosions. [hide full abstract] Member Price: Free      Nonmember Price: Free

Science Object

Chemical Reactions: A World of Reactions Grade Level: Elementary School, Middle School Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the first of four Science Objects in the Chemical Reactions SciPack. It explains that chemical reactions occur all around us, for example in health care, cooking, cosmetics, and automobiles. An enormous variety of biological, chemical, and physical phenomena can be explained by changes...  [view full summary] Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the first of four Science Objects in the Chemical Reactions SciPack. It explains that chemical reactions occur all around us, for example in health care, cooking, cosmetics, and automobiles. An enormous variety of biological, chemical, and physical phenomena can be explained by changes in the arrangement and motion of atoms and molecules. An atom's electron configuration, particularly the outermost electrons, determines how the atom can interact with other atoms. Atoms form bonds to other atoms by transferring or sharing electrons. Carbon atoms can bond to one another in chains, rings, and branching networks to form a variety of structures, and complex chemical reactions involving these molecules take place constantly in every cell in living objects. [hide full abstract] Member Price: Free      Nonmember Price: Free