10F/H1 ( Grades: 9-12 ): In the late 1700s and early 1800s, the idea of atoms reemerged in response to questions about the structure of matter, the nature of fire, and the basis of chemical phenomena.
10F/H3 ( Grades: 9-12 ): In the early 1800s, British chemist and physicist John Dalton united the concepts of atoms and elements. He proposed two ideas that laid the groundwork for modern chemistry: first, that elements are formed from small, indivisible particles called atoms, which are identical for a given element but different from any other element; and second, that chemical compounds are formed from atoms by combining a definite number of each type of atom to form one molecule of the compound.
10F/H5 ( Grades: 9-12 ): Since Lavoisier and Dalton, the system for describing chemical reactions has been vastly extended to account for the configuration taken by atoms when they bond to one another and to describe the inner workings of atoms that account for why they bond as they do.
10F/M4 ( Grades: 6-8 ): Antoine Lavoisier's work was based on the idea that when materials react with each other, many changes can take place but that in every case the total amount of mass afterward is the same as before. He successfully tested the concept of conservation of mass by conducting a series of experiments in which he carefully measured all the substances involved in burning, including the gases used and those given off. As a result, the phlogiston theory was replaced by a theory based on the role of oxygen in burning.
11C/H1 ( Grades: 9-12 ): If a system in equilibrium is disturbed, it may return to a very similar state of equilibrium, or it may undergo a radical change until the system achieves a new state of equilibrium with very different conditions, or it may fail to achieve any type of equilibrium.
11C/H10 ( Grades: 9-12 ): Whatever happens within a system, such as parts exploding, decaying, or reorganizing, some features, such as the total amount of matter and energy, remain precisely the same.
11C/H11 ( Grades: 9-12 ): The amount of something in a system may stay the same because nothing is happening to it or because it is being transformed into something else at the same rate as something else is being transformed into it.
4D/E2 ( Grades: 3-5 ): No matter how parts of an object are assembled, the weight of the whole object is always the same as the sum of the parts; and when an object is broken into parts, the parts have the same total weight as the original object.
4D/E8 ( Grades: 3-5 ): Substances may move from place to place, but they never appear out of nowhere and never just disappear.
4D/H10 ( Grades: 9-12 ): The physical properties of compounds reflect the nature of the interactions among its molecules. These interactions are determined by the structure of the molecule, including the constituent atoms and the distances and angles between them.
4D/H2 ( Grades: 9-12 ): The number of protons in the nucleus determines what an atom's electron configuration can be and so defines the element. 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.
4D/H7 ( Grades: 9-12 ): An enormous variety of biological, chemical, and physical phenomena can be explained by changes in the arrangement and motion of atoms and molecules.
4D/H8 ( Grades: 9-12 ): The configuration of atoms in a molecule determines the molecule's properties. Shapes are particularly important in how large molecules interact with others.
4D/H9a ( Grades: 9-12 ): The rate of reactions among atoms and molecules depends on how often they encounter one another, which is affected by the concentration, pressure, and temperature of the reacting materials.
4D/H9b ( Grades: 9-12 ): Some atoms and molecules are highly effective in encouraging the interaction of others.
4D/M10 ( Grades: 6-8 ): A substance has characteristic properties such as density, a boiling point, and solubility, all of which are independent of the amount of the substance and can be used to identify it.
4D/M11 ( Grades: 6-8 ): Substances react chemically in characteristic ways with other substances to form new substances with different characteristic properties.
4D/M4 ( Grades: 6-8 ): The temperature and acidity of a solution influence reaction rates. Many substances dissolve in water, which may greatly facilitate reactions between them.
4D/M5 ( Grades: 6-8 ): Chemical elements are those substances that do not break down during normal laboratory reactions involving such treatments as heating, exposure to electric current, or reaction with acids. All substances from living and nonliving things can be broken down to a set of about 100 elements, but since most elements tend to combine with others, few elements are found in their pure form.
4D/M7a ( Grades: 6-8 ): No matter how substances within a closed system interact with one another, or how they combine or break apart, the total mass of the system remains the same.
4D/M7b ( Grades: 6-8 ): The idea of atoms explains the conservation of matter: If the number of atoms stays the same no matter how the same atoms are rearranged, then their total mass stays the same.
4G/H1 ( Grades: 9-12 ): vitational force is an attraction between masses. The strength of the force is proportional to the masses and weakens rapidly with increasing distance between them.
5A/M1 ( Grades: 6-8 ): One of the most general distinctions among organisms is between plants, which use sunlight to make their own food, and animals, which consume energy-rich foods. Some kinds of organisms, many of them microscopic, cannot be neatly classified as either plants or animals.
NSTA National Science Education Standards
B.1.2 ( Grades: 5-8 ): Substances react chemically in characteristic ways with other substances to form new substances (compounds) with different characteristic properties. In chemical reactions, the total mass is conserved. Substances often are placed in categories or groups if they react in similar ways; metals is an example of such a group.
B.2.3 ( Grades: 9-12 ): Bonds between atoms are created when electrons are paired up by being transferred or shared. A substance composed of a single kind of atom is called an element. The atoms may be bonded together into molecules or crystalline solids. A compound is formed when two or more kinds of atoms bind together chemically.
B.2.4 ( Grades: 9-12 ): The physical properties of compounds reflect the nature of the interactions among its molecules. These interactions are determined by the structure of the molecule, including the constituent atoms and the distances and angles between them.
B.2.6 ( Grades: 9-12 ): Carbon atoms can bond to one another in chains, rings, and branching networks to form a variety of structures, including synthetic polymers, oils, and the large molecules essential to life.
B.3.3 ( Grades: 9-12 ): 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. Radical reactions 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.
B.3.5 ( Grades: 9-12 ): Catalysts, such as metal surfaces, accelerate chemical reactions. Chemical reactions in living systems are catalyzed by protein molecules called enzymes.