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Unit 1: Introduction to Scientific Methods atom: the smallest part of an element that can exist. It consists of a nucleus of protons and neutrons, surrounded by orbiting electrons. capacity: the amount of liquid an object can hold. condensation: when a gas turns into a liquid. convection: the transfer of heat through a gas or liquid by currents within the gas or liquid. density: the mass of an object divided by the volume of an object. More generally, density refers to how massive and tightly together the molecules in an object are packed. density of water: because the metric system initially used water to define the basic units of measurement for volume and mass, the density of water is equal to 1 gram / 1 millimeter. Any object with a density less than 1g/ml will float in water, and any object with a density more than 1g/ml will sink in water. direct measurement: finding the volume of a rectangular prism by multiplying the length of the object by its height of the object, and then multiplying the product times the width of the object. It is important that the measurements for length, width, and height are taken using the same units. displacement: the volume of water that an object "pushes aside," or displacements when submersed completely under water. element: a substance that cannot be broken down into more simple substances by chemical reactions. energy: the capacity to do work. evaporation: when a liquid turns into a gas. experiment: in an experiment, you make a comparison between two situations, keeping all things the same except one. Experiments have "controls" or comparison groups. freezing: when a liquid turns into a solid. heat: the energy that an object has because its molecules are moving. hypothesis: an hypothesis is a statement given as an explanation for something that happens (see p. 87 of Dry Ice GEMS guide for a more complete discussion). International System of Units: abbreviated SI, the International System of Units is a set of standard measurement units that builds on the metric system. The key feature of this system is that conversion between smaller and larger units of measurement is based on a multiples of 10 (see the support materials in Lesson 20 for a complete explanation of the International System of Units). investigable question: an investigable question is something possible to answer through doing an experiment or a systematic observation. kinetic molecular theory: when heat is added to an object, the molecules
that make up the object move faster and farther apart. melting: when a solid turns into a liquid. molecule: the smallest unit of an element or compound. A molecule is made up of at least two atoms. outcome variable: an outcome variable is the result you compare in an experiment (sometimes referred to as the dependent or responding variable). particulate model of matter: all matter is made up of tiny, moving particles, called atoms. Atoms are too small to be seen with an ordinary microscope. Individual atoms combine to form molecules. There is space between molecules, and they are always moving. When heat is added to an object, the molecules that make up the object move faster and farther apart. phases: the three states in which matter occurs: solid, liquid, and gas, or vapor. phase change: when matter turns from one state into another. qualitative data: descriptions of events that do not use numbers If you report colors, smells, tastes, textures, or sounds, for example, you are making qualitative observations. quantitative data: descriptions of events that do include numbers. If you count objects, or measure them with standard units, you are making quantitative observations. Quantitative observations are often made using tools. sublimation: when a solid turns into a gas without first becoming a liquid. surface tension: an effect that makes a liquid seem as though it has an elastic "skin." It is caused by cohesion between the surface molecules. temperature: a measure of how hot or cold something is. More specifically, temperature is a measure of how fast the molecules in an object are moving. test variable: a test variable is the one thing you plan to be different in an experiment (sometimes referred to as the independent or controlling variable). systematic observation: In a systematic observation, you make a plan, decide on the conditions, follow the plan, and then carefully observe and record what happens over time. variable: A variable is something which can vary each time you do something. volume: the space occupied by matter. Unit 1 Introduction amnd Overview Lesson 1: Laboratory Safety and Classroom Management Lesson 2: Observation and Inference Lesson 3: Introduction to Observation Lesson 4: Comparing H2O to CO2 Lesson 7: Marge's Systematic Observation Lesson 10: Investigable Questions Lesson 11: Planning an Investigation Lesson 12: Conducting Investigations Lesson 15: Layering Salt Solutions Lesson 16: Density in Everyday Life Lesson 17: Observing Convection Lesson 18: Understanding Convection Lesson 20: Intro to Measurement Lesson 21: How Big is my Favorite Stuffed Animal? |
