Download 8th Grade Post Physical Science Test Study Guide PS 1: The

8th Grade Post Physical Science Test Study Guide
PS 1: The student will demonstrate an understanding of scientific reasoning, logic and the nature of science by
planning and conducting investigations in which…
 B. length, mass, volume, density, temperature, weight, and force are accurately measured.
 Triple beam balance: measures mass
 Thermometer: measures temperature
 Ruler: measures length
 Graduated cylinder: measures liquid volume
 Spring Scale: measures force
 D. triple beam and electronic balances, thermometers, metric rulers, graduated cylinders and spring
scales are used to gather data
 Examples:
Metric Ruler
triple beam balance
Graduated Cylinder
thermometer
PS 2: The student will investigate and understand the basic nature of matter.
 B. Matter can be classified as elements, compounds, and mixtures. The atoms of any element are alike but
are different from atoms of other elements. Compounds consist of two or more elements that are
chemically combined in a fixed ratio. Mixtures also consist of two or more substances, but the substances
are not chemically combined.
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B. Compounds are 2 or more elements that are chemically combined.
Example of elements – B, Na, C, Cl.
Example of compounds - NaCl, KCl, KI, NH3
 Element Symbols have either 1 capital letter or 1 capital letter and a lower case letter so if it is a
compound there will be 2 or more capital letters.
B. Solute, Solvent: Solute – substance being dissolved
Solvent - substance doing the dissolving.
Sugar = solute
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Coffee = solvent
E. Chemical properties: acidity, basicity, combustibility, and reactivity.
E. Physical Properties: density, boiling point, solubility, shape, odor, melting point, boiling point and
color.
 Formula for calculating density: density = mass
Volume
Example: Density = 10g
2 mL
= density = 5 g/mL
Mass is measured in grams (base unit), volume measured in , ml, cm3
Units for density: g/cm3, g/mL
F. Characteristics of types of matter based on physical and chemical properties. Acids and Bases.
 Acid: pH below 7, produces hydrogen ions (H+)
 Base: pH above 7, produces hydroxide ions (OH-)
 pH 7: Neutral
PS 3: The student will investigate and understand the modern and historical models of atomic structure.
 A. The contributions of Dalton, Thomson, Rutherford, and Bohr in understanding the atom.
 Dalton: said the atom was a solid sphere, stated that all elements are made of indestructible
particles called atoms that all are alike
 Thomson: discovered the negatively charged particle
 Rutherford: added the concept of the nucleus to the modern model
 Bohr: added the concept of electron obits to the modern model
 Modern Atomic Theory: have a large cloud like region where the electrons are constantly
moving around the nucleus.
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Atomic structure:
Protons = positive charge (found in the nucleus)
Neutrons = neutral charge (found in the nucleus)
Electrons = negative charge (found in the electron cloud/orbit)
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Modern Atomic Theory
PS 4: The student will investigate and understand the organization and use of the periodic table of elements to
obtain information.
 A. symbols, atomic number, atomic mass, chemical families (groups), and periods.
Atomic number = number of protons and number of electrons – in Carbon there are 6 protons and 6
electrons
Atomic weight (mass) = number of protons + neutrons.
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C. formation of compounds through ionic and covalent bonding
 Counting atoms: subscript tells how many atoms of the element that it is behind. Coefficient the
number goes with the entire compound.
 Example: O2 is Oxygen with a subscript of 2 telling us there are 2 atoms of Oxygen.
 Example: CO2 is carbon dioxide contains 1 atom of carbon and 2 atoms of oxygen for a total of 3
atoms in the compound.
 Example: 2H2O is 2 molecules of water. It contains 4 atoms of hydrogen and 2 atoms of oxygen.
There is a total of 6 atoms in this compound.
PS 5: The student will investigate and understand changes in matter and the relationship of these changes to the
Law of Conservation of Matter and Energy.
 A. Physical changes: the chemical composition (make up) of the substance does not change. Examples:
tearing a piece of paper, folding a piece of paper, melting ice., boiling water.
 B. Chemical change: a different substance is formed. Examples: burning something, chemical reactions like
coming sodium and chlorine to form table salt, digesting food.
 Law of Conservation of Matter (Mass): In a closed system matter/energy is neither created or destroyed, it
is simply changed (the total mass remains the same). For this reason chemical equations must be balanced.
= same number of atoms on both sides of the equation.
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Chemical Equations contain: Reactants --- Products
Baking Soda + Vinegar --- Water + Salt + Carbon Dioxide gas
(reactants)
(products)
Na (sodium) + Cl (chlorine) - NaCl (sodium chloride)
(reactants)
-
(products)
The arrow points to the products.
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C. Endothermic and Exothermic Reactions
 Endothermic Reaction: reaction that takes in heat energy/absorbed (feel cold) Example: baking
soda and vinegar reaction
 Exothermic Reaction: chemical reaction where heat energy is given off (feel hot) Example: calcium
hydroxide (melt ice on roads)
PS 6: The student will investigate and understand states and forms of energy and how energy is transferred and
transformed.
 A. Potential and Kinetic Energy (the 2 states of energy)
 Energy is the ability to do work.
 Potential energy = stored energy (amount depends on position) = example: car sitting at the top of a
hill
 Kinetic energy = the energy of motion (amount depends on mass and velocity of the object) =
example: car begin driven down a road
 Law of Conservation of Energy: energy is neither created or destroyed, it is transferred from one
form to another. Example: pendulum – as the pendulum swings the energy is constantly changing
from potential to kinetic to potential to kinetic …..
 Energy conversion/transformation examples:
1. flashlight: chemical (battery) to electrical to radiant (light) and heat (thermal).
2. Toaster: electrical to mechanical to radiant to thermal
3. Microwave: electrical to mechanical to radiant to thermal and sound
 B. Mechanical, chemical, electrical energy, thermal, radiant and nuclear energy
 Mechanical energy: the total of potential + kinetic energy in a system
 Chemical energy: energy stored in chemical bonds
 Electrical energy: energy of moving electric charges
 Thermal energy: energy that comes from internal vibration of atoms and molecules
 Radiant energy: energy that travels in transverse waves
 Nuclear energy: energy stored in the nucleus of an atom
PS 7: The student will investigate and understand temperature scales, heat and thermal energy transfer.
 A. Celsius and Kelvin temperature scales and absolute zero.
 0o C = freezing point of water (also the melting point)
 100o C = boiling point of water
 0 K or Absolute zero = the theoretical point at which all motion stops.
 B. phase change, freezing point, melting point, boiling point, vaporization and condensation
Phase Change Graph
Description of graph: water begins as a solid – heat is added so the temperature begins to rise – when it reaches 0o
C (the melting point) it begins to melt it is changing from a solid to a liquid (during the phase change the
temperature stays the same) – once the water is completely melted the temperature begins to rise until it reaches
the boiling point at 1000 C – as the liquid boils the temperature remains the same (phase change) and the water is
changing to a gas after the phase change the temperature will begin to rise.
 The flat lines on the graph indicate PHASE CHANGES.
 Solid to liquid
 Liquid to gas
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 C. Methods of Heat Transfer: conduction, convection, radiation
 Conduction: heat transfer through direct contact.
 examples: touching a hot iron with your finger, the pot sitting on the stove, spoon in a hot
liquid getting hot.
Conduction (spoon getting hot in the bowl of soup)
 Convection: movement in a gas or liquid in which the warmer parts move up and the colder
parts move down; the transfer of heat by this movement
examples: heating soup in a pan, heating or cooling our homes
 Radiation: the transfer of energy in the form of waves; does not require matter
Examples: feeling the heat from a campfire, the sun
PS 8: The student will investigate and understand characteristics of sound and technological applications of sound
waves.
 A. wavelength, frequency, speed, amplitude, rarefaction and compression
 Parts of a transverse wave: amplitude, crest, trough, wavelength
 Amplitude: the measurement from rest to crest or rest to trough
 Crest: the high point of the wave
 Trough: the low point of the wave
 Wavelength: the measurement from crest to crest or trough to trough
 Parts of a Compression Wave
 Rarefaction: the least dense part (more spread out)
 Compression: the most dense part (close together)
 Wave Frequency: number of wavelengths that pass a given point per second (measured in
hertz)
 As frequency increases the wavelength decreases, as frequency decreases wavelength
increases.
 Sound: as wave frequency increases the pitch increases
PS 9. The student will investigate and understand the characteristics of transverse waves.
 B . the wave behavior of light
 Reflection: occurs when a wave strikes an object or surface and bounces off
 Refraction: bending of a wave as it moves from one medium into another medium; due to a
change in speed.
 Diffraction: bending of waves around a barrier.
 D. the electromagnetic spectrum: the entire range of electromagnetic wave frequencies (radio waves,
microwaves, infrared, visible light, ultraviolet waves, x-rays, and gamma rays) The waves are arranged on
the spectrum according to wavelength – radio waves have the longest and gamma rays the shortest
wavelength.
 VISIBLE LIGHT SPECTRUM: ROYGBV: arranged in the order of wavelength with red as the longest
and violet the shortest.
PS 10: The student will investigate and understand scientific principles and technological applications of work,
force and motion.
 A. speed, velocity and acceleration
 Speed is rate of change of position (formula: S = D/T)
 Velocity is speed and direction of a moving object (ex. 10 m/s north)
 Acceleration is the change in velocity per unit of time (formula is Vf - Vi )
T
 B. Newton’s Laws of Motion
 Gravity is force exerted by every object in the universe on every other object. The force of gravity
can cause some objects to move for example and object sliding or rolling downhill.
 Mass and Weight are not the same; mass is the amount of matter in an object and weight is the
amount of force of gravity it takes to hold a mass down.
 Newton’s First Law: (inertia) states an object in motion will stay in motion and an object at rest
will stay at rest unless acted upon by an unbalanced force.
(1st Law)
 Newton’s Second Law: Force = Mass x Acceleration (F=M x A)
 Newton’s Third Law: For every action there is an equal and object reaction.
PS 11: The student will investigate and understand basic principles of electricity and magnetism.
 Static electricity, current electricity and circuits
 Static electricity: friction can cause electrons to be transferred from one object to another – these
electrical charges can build up on an object and be discharged slowly or rapidly. Examples of static
electricity – clothes in a dryer sticking together, rubbing your hair with a balloon
 Current Electricity: the flow of electrons through a wire or other conductor. Example: electricity in
your home. Current electricity is our homes is measured in kilowatt – hour.
 Relationship between a magnetic field and an electric current
 Magnetic field is the region around a magnet where magnetic forces act.
 Magnetic items: examples – iron, sterling silver, paper clips etc.
S.Mair
Jones Magnet Middle School