FTCE K-6 Elementary Science

How is a chemical reaction different from and a physical reaction? - Answer- A physical change is reversible, a chemical change is not. For example, the freezing of water would be a physical change because it can be reversed, whereas the burning of wood is a chemical change - you can't 'unburn' it What is the difference between an element, a compound, and a mixture? - Answer- An element is made up only one kind of atom, and cannot be broken down into simpler substances by chemical reactions Examples: oxygen, carbon, sulfur, zinc, hydrogen A compound is made up of two or more elements that have chemically combined and cannot be separated easily. Examples: water (H20 - hydrogen, oxygen) or Table Salt (NaCl - Sodium, Chloride) A mixture is a combination of two or more materials that does not include a chemical reaction and all materials keep their properties. Examples: air, sand, muddy water, blood What is the difference between a solute and a solvent? - Answer- Solute - the dissolved substance in a solution (ex. sugar, salt) Solvent - a liquid substance capable of dissolving other substances (ex. water) Identify the basic components of the atom (i.e., electrons, neutrons, protons). - Answer- Proton - positively charged particle Electron - negatively charged particle (when they move they cause heat) Neutron - neutral particle *Atoms of the same element with a different number of neutrons are called Isotopes How do you convert Celsius to Fahrenheit and vice versa - Answer- Celsius to Fahrenheit is calculated by multiplying by 1.8 and then adding 32 degrees! Fahrenheit to Celsius is calculated by subtracting 32 degrees and then dividing by 1.8! Know the different types of forces of motion: - Answer- Mechanical- forces that relate to machines, include actions performed or worked by machinery Magnetic- forces that electrical charges experience while moving in a magnetic field Gravitational- forces of attraction between all objects in the universe Electrostatic- forces that exist between two charged particles (like charges repel and unlike charges attract) Know general information about simple machines - Answer- pulleys, levers, incline planes, wheel and axle, wedge, or a screw. What is the Doppler Effect? - Answer- The Doppler Effect is a theory that explains the change in frequency of a wave of either sound or light, in relation to the distance between