8-3. Each of the more than 100 elements of matter has distinct properties and a distinct atomic structure. As a basis for understanding this concept:
Students know the structure of the atom and know it is composed of protons, neutrons, and electrons.
Students know that compounds are formed by combining two or more different elements, and that compounds have properties that are different from their constituent elements.
Students know atoms and molecules form solids by building up repeating patterns, such as the crystal structure of NaCl or long-chain polymers.
Students know the states of matter (solid, liquid, gas) depend on molecular motion.
Students know that in solids the atoms are closely locked in position and can only vibrate; in liquids the atoms and molecules are more loosely connected and can collide with and move past one another; and in gases the atoms and molecules are free to move independently, colliding frequently.
Students know how to use the periodic table to identify elements in simple compounds. 5-1-b. Students know all matter is made of atoms, which may combine to form molecules. 5-1-f. Students know differences in chemical and physical properties of substances are used to separate mixtures and identify compounds. 5-1-g. Students know properties of solid, liquid, and gaseous substances, such as sugar (C6H12O6), water (H2O), helium (He), oxygen (O2), nitrogen (N2), and carbon dioxide (CO2). 5-1-i. Students know the common properties of salts, such as sodium chloride (NaCl). 4-4-b. Students know how to identify common rock-forming minerals (including quartz, calcite, feldspar, mica, and hornblende) and ore minerals by using a table of diagnostic properites.
8-5. Chemical reactions are processes in which atoms are rearranged into different combinations of molecules. As a basis for understanding this concept:
Students know reactant atoms and molecules interact to form products with different chemical properties.
Students know the idea of atoms explains the conservation of matter: In chemical reactions the number of atoms stays the same no matter how they are arranged, so their total mass stays the same.
Students know chemical reactions usually liberate heat or absorb heat.
Students know physical processes include freezing and boiling, in which a material changes form with no chemical reaction.
Students know how to determine whether a solution is acidic, basic, or neutral. 5-1-a. Students know that during chemical reactions the atoms in the reactants rearrange to form products with different properties.
Chemistry of Living Systems (Life Science)
8-6. Principles of chemistry underlie the functioning of biological systems. As a basis for understanding this concept:
Students know that carbon, because of its ability to combine in many ways with itself and other elements, has a central role in the chemistry of living organisms.
Students know that living organisms are made of molecules consisting largely of carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.
Students know that living organisms have many different kinds of molecules, including small ones, such as water and salt, and very large ones, such as carbohydrates, fats, proteins, and DNA. 5-1-h. Students know living organisms and most materials are composed of just a few elements.
8-7. The organization of the periodic table is based on the properties of the elements and reflects the structure of atoms. As a basis for understanding this concept:
Students know how to identify regions corresponding to metals, nonmetals, and inert gases.
Students know each element has a specific number of protons in the nucleus (the atomic number) and each isotope of the element has a different but specific number of neutrons in the nucleus..
Students know substances can be classified by their properties, including their melting temperature, density, hardness, and thermal and electrical conductivity. 5-1-c Students know metals have properties in common, such as high electrical and thermal conductivity. Some metals, such as aluminum (Al), iron (Fe), nickel (Ni), copper (Cu), silver (Ag), and gold (Au), are pure elements; others, such as steel and brass, are composed of a combination of elemental metals. 5-1-d Students know that each element is made of one kind of atom and that the elements are organized in the periodic table by their chemical properties.
8-8. All objects experience a buoyant force when immersed in a fluid. As a basis for understanding this concept:
Students know density is mass per unit volume.
Students know how to calculate the density of substances (regular and irregular solids and liquids) from measurements of mass and volume.
Students know the buoyant force on an object in a fluid is an upward force equal to the weight of the fluid the object has displaced.
Students know how to predict whether an object will float or sink.
8-9. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will:
|Plan and conduct a scientific investigation to test a hypothesis.|
|Evaluate the accuracy and reproducibility of data.|
|Distinguish between variable and controlled parameters in a test.|
|Recognize the slope of the linear graph as the constant in the relationship y=kx and apply this principle in interpreting graphs constructed from data.|
|Construct appropriate graphs from data and develop quantitative statements about the relationships between variables.|
|Apply simple mathematical relationships to determine a missing quantity in a mathematic expression, given the two remaining terms (including speed = distance/time, density = mass/volume, force = pressure x area, volume=area x height).|
|Distinguish between linear and non-linear relationships on a graph of data.|
|Students know scientists have developed instruments that can create discrete images of atoms and molecules that show that the atoms and molecules often occur in well-ordered arrays.|
5-6 Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will:
|Classify objects (e.g., rocks, plants, leaves) in accordance with appropriate criteria.|
|Develop a testable question.|
|Plan and conduct a simple investigation based on a student-developed question and write instructions others can follow to carry out the procedure.|
|Identify a single independent variable in a scientific investigation and explain how this variable can be used to collect information to answer a question about the results of the experiment.|
|Select appropriate tools (e.g., thermometers, meter sticks, balances, and graduated cylinders) and make quantitative observations.|
Record data by using appropriate graphic representations (including charts, graphs, and labeled diagrams) and make inferences based on those data.
|Draw conclusions from scientific evidence and indicate whether further information is needed to support a specific conclusion.|
|5-6-h.||Write a report of an investigation that includes conducting tests, collecting data or examining evidence, and drawing conclusions.|