* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download General Science Mr. Tiesler Mid Term Exam Study Guide Scientific
Survey
Document related concepts
Low-carbon economy wikipedia , lookup
International Energy Agency wikipedia , lookup
Alternative energy wikipedia , lookup
Energy returned on energy invested wikipedia , lookup
Energy efficiency in transport wikipedia , lookup
Internal energy wikipedia , lookup
Negawatt power wikipedia , lookup
Energy policy of the European Union wikipedia , lookup
Photoelectric effect wikipedia , lookup
Conservation of energy wikipedia , lookup
Energy Independence and Security Act of 2007 wikipedia , lookup
Transcript
Name: _________________________ Date: _____________ General Science Mr. Tiesler Mid Term Exam Study Guide Scientific Method The scientific method is a step by step process by which scientists answer questions The steps of the scientific method are: 1. 2. 3. 4. 5. 6. 7. 8. 9. Make an observation Ask a question Research the topic Form a hypothesis Test the hypothesis Gather data Analyze results Draw conclusions Communicate results The Independent Variable is the factor the scientist changes to test a hypothesis. The Dependent Variable is the factor the scientist observes and measures. The Control Variable if the factor the scientist does not change (remains constant). The Experimental Group is the part of the experiment that contains the independent variable. The Control Group is the part of the experiment that does not contain the independent variable and is use for comparison. A Scientific Theory is a summary of a pattern found in nature. Explains why thing happen A Scientific Law is an explanation of a pattern found in nature. Explains how things work A Scientific Model is a representation of an object or system found in nature. The System Internationale (SI), also known as the metric system, is the system scientists (and the majority of the world) use measure and record data. The meter is the base unit for length The kilogram is the base unit for mass The liter is the unit for volume Energy Energy is the ability to do work. Kinetic Energy is the energy associated with the motion of an object. 1 𝐾𝐸 = 2 𝑚𝑣 2 Gravitational Potential Energy is the energy associated with the position of an object. 𝑃𝐸 = 𝑚𝑔ℎ, 𝑤ℎ𝑒𝑟𝑒 𝑔 = 9.8 𝑚⁄𝑠 2 Elastic Potential Energy is the energy associated with an object that is stretched or compressed. Thermal Energy is the total kinetic and potential energy associated with the atoms and molecules of an object. Energy associated with the heat of an object Chemical Energy is the energy stored in the chemical bonds between atoms. Electrical Energy is the energy associated with electrical charges. Electromagnetic Energy is energy that travels in waves. Includes energy from visible light, gamma rays, x-rays, ultraviolet rays, infrared rays, microwaves and radio waves Nuclear Energy is the energy stored in the nucleus of an atom. Fission is the energy released when the nucleus of an atom is split apart Fusion is the energy released when two small nuclei are fused together to form one large nucleus The Law of Conservation of Energy states that energy cannot be created or destroyed but it can be converted from one form to another. Heat is the transfer of thermal energy from one object to another due to a temperature difference. Flows spontaneously from hot objects to cold objects Temperature is the measure of how hot or cold an object is based on a reference point. Temperature is measured in degrees Fahrenheit, degrees Celsius, of Kelvin The freezing point of water on the Fahrenheit scale is 32o The boiling point of water on the Fahrenheit scale is 212o The freezing point of water on the Celsius scale is 0o The boiling point of water on the Celsius scale is 100o Absolute Zero on the Kelvin scale is equivalent to -273oC Specific Heat is the amount of energy needed to raise the temperature of one gram of a substance by one degree Celsius. Conduction is the transfer of thermal energy without the transfer of matter. Can occur between particles of the same material Can occur between particles of different materials Thermal Conductors are materials that easily conduct thermal energy o Metals Thermal Insulators are materials that do not conduct thermal energy o Wood, Air, Glass Convection is the transfer of thermal energy when particles of a fluid move from one location to another. Radiation is the transfer of thermal energy by waves moving through space. Atomic Theory The Greek philosopher Democritus was the first to theorize that all matter was made of tiny particles that could not be divided. He called these tiny particles “atoms” o Greek for indivisible Aristotle stated that all matter was made of four elements Earth Air Fire Water Dalton’s Atomic Theory: All elements are composed of atoms All elements of the same element have the same mass Atoms of different elements have different masses Compounds contain more than one element In compounds, elements always combine in the same ratios J.J. Thompson’s Atomic Theory: Used electric currents to study atoms Discovered the electron Atom was a solid, positively charged sphere with small, negatively charged electrons embedded within it. (Plum Pudding model) Ernest Rutherford’s Atomic Theory: Protons are positively charged particles found in the nucleus Electrons are negatively charged particles orbiting the nucleus Bohr’s Atomic Model: Electrons move in fixed orbits around nucleus Different orbits represent different energy levels Electrons can move between energy levels as they gain or lose energy The closer to the nucleus, the lower the energy of an electron The further away from the nucleus, the higher the energy of the electron Electron Cloud Model: Electrons do not travel around the nucleus in fixed orbits like planets orbiting the Sun It is impossible to pinpoint the exact location of an electron at any given moment o Propellers on a plane Electron Cloud – A visual model of the most likely locations for an electron Neutrons, particles with no charge located in the nucleus, discovered by James Chadwick in 1932. Protons and Neutrons have about the same mass, electrons are 2,000 times smaller than protons and neutrons. The Atomic Number equals the number of protons in the nucleus Every element has a different number of protons The Atomic Mass is the sum of the protons and neutrons in the nucleus. # of neutrons = atomic mass – atomic number Atomic mass is a weighted average of the different isotopes of an element Isotopes are atoms of the same element that have different numbers of neutrons. Periodic Table Dmitri Mendeleev created first useful table of known elements. Based table on solitaire game Arranged elements by increasing atomic mass Divided elements into rows so that elements with similar properties were in the same column Left blank spaces for undiscovered elements Modern periodic table arranged by increasing atomic number Mendeleev didn’t know about protons o Protons hadn’t been discovered yet Periods are the horizontal rows on the periodic table. Each period is associated with the highest energy level of electrons There are seven periods on the periodic table Electrons in the outermost energy level (shell) are Valance Electrons Groups are the vertical columns on the periodic table. Elements within the same group have similar properties Elements in the same group have the same number of valance electrons The three classes of elements are Metals, Nonmetals, and Metalloids. The majority of elements are metals Bromine (nonmetal) and Mercury (metal) are the only elements that are liquid at room temperature Alkali Metals are Group One metals Lithium, Sodium, Potassium, Rubidium, Cesium, Francium Highly reactive Only found in compounds in nature Alkali Earth Metals are Group Two elements Halogens are Group Seven elements. Highly reactive Noble Gases are Group Eight elements. Nonreactive Stable electron configurations Elements will gain, lose or share electrons to achieve electron configuration of nearest noble gas Ionic Bond – Chemical bond where electrons are transferred from one atom to another. Covalent Bond – Chemical bond where two atoms share a pair of electrons. Polar Covalent Bond – Electrons are not shared equally between atoms Carbon atoms have four valance electrons. Can form single, double, or triple covalent bonds Is found in millions of compounds Is the basis of all life as we know it Organic Compounds are compounds that contain hydrogen and carbon.