Science Review for Georgia High School Science Graduation Test

1. Science Review forGeorgia High School Science Graduation Test “Education is what remains after one has forgotten everything he learned in school.” – Albert Einstein

2. GHSGT CONTENT • Forces, Waves, & Electricity (15%-17%) • Energy Transformations (15%-17%) • Cells & Heredity (24%-26%) • Structure & Properties of Matter (25%-27%) • Ecology (16%-18%)

3. Forces, Waves, and Electricity (15%-17%)

4. Forces, Waves, and Electricity Part 1 - Velocity • Calculate velocity. Velocity is speed in a direction. Speed is distance / time or s = d/t • Example: Biscuit ran 120 meters in 20 seconds. How fast was he going? • Distance = • Time =

5. Forces, Waves, and Electricity Part 1 - Velocity • Calculate velocity. Velocity is speed in a direction. Speed is distance / time or s = d/t • Example: Biscuit ran 120 meters in 20 seconds. How fast was he going? • Distance = 120 m • Time = 20 s • Speed = 120 m / 20 s = 6 m/s • If we said he ran at a speed of 6 m/s and named the direction he was running, that would be his velocity.

6. Forces, Waves, and Electricity Part 2 - Acceleration • Calculate acceleration. Acceleration is the rate that the velocity is changing. Acceleration equals the change in velocity divided by the time. • a = (vf –vi) /t • Example: Super-Fred was flying along at a speed of 15 m/s when he spotted a kitten stuck in a tree. In just 4 seconds, he sped up to 23 m/s in order to rescue it. What was his acceleration?

7. Forces, Waves, and Electricity Part 2 - Acceleration • Calculate acceleration. Acceleration is the rate that the velocity is changing. Acceleration equals the change in velocity divided by the time. • a = (vf –vi) /t • Example: Super-Fred was flying along at a speed of 15 m/s when he spotted a kitten stuck in a tree. In just 4 seconds, he sped up to 23 m/s in order to rescue it. What was his acceleration? • vf = 23 m/s (his velocity after speeding up) • vi = 15 m/s (his velocity before speeding up) • t = 4 s (how long it took him to speed up) • a = (23 m/s – 15 m/s) / 4 s • a = 8 m/s / 4 s • a = 2 m/s2 What this is saying is that he got 2 m/s faster every second that he sped up.

8. Forces, Waves, and Electricity Part 3 – Newton’s Laws of Motion • 1st Law- (Law of Inertia) Objects at rest remain at rest unless acted on by a net force. Objects in motion remain in motion at a constant velocity unless acted on by a net force. The easy way to say this is that it takes a push or a pull to make anything change velocity. • 2nd Law- Force is equal to mass times acceleration (F = m•a). If something has more mass, it is harder to make it speed up, slow down, or change direction. Force is measured in Newtons. 1 N = 1 kg • m/s2 • 3rd Law- For every action force, there is an equal and opposite reaction force. This is what makes rockets work. If you push something in one direction, it pushes you back in the opposite direction. When you are driving a car, the drive wheel is pushing backward against the road and the road is pushing the car forward.

9. Forces, Waves, and Electricity Part 4 – Gravity, Mass, and Weight • Gravity is a force that attracts everything in the universe with mass to everything else in the universe that has mass. The force of gravity between to things depends on the mass and the distance separating them. More mass means more force and more distance means less force. On Earth, falling things ACCELERATE at almost 10 m/s2 (Actually 9.8 m/s2) • Mass is basically how much STUFF makes up something. Your mass is the same everywhere in the universe. • Weight is just a measure of how strong the force of gravity is on you. That means that your weight is much less on the Moon than on Earth (since the Moon has less mass, it has a smaller force of gravity with you) but your mass is still the same there.

10. Forces, Waves, and Electricity Part 5 –Work • Work- Work is the energy used when a force makes something move. It requires 2 things: object must move and motion of object must be in same direction as force. • Work is equal to force times distance. That means more force or more distance means more work. W = f • d . Work is measured in N•m (Newton meters) which we call Joules (J). • Example: If it took a force of 45 N to move a box 8 m, how much work did you do? • f = • d =

11. Forces, Waves, and Electricity Part 5 –Work • Work- Work is the energy used when a force makes something move. It requires 2 things: object must move and motion of object must be in same direction as force. • Work is equal to force times distance. That means more force or more distance means more work. W = f • d . Work is measured in N•m (Newton meters) which we call Joules (J). • Example: If it took a force of 45 N to move a box 8 m, how much work did you do? • f = 45 N • d = 8 m • W = (45 N) (8 m) = 360 N•m = 360 J

12. Forces, Waves, and Electricity Part 6 – Mechanical Advantage of Simple Machines • Mechanical Advantage (MA) the number of times a machine multiplies the effort force. MA = resistance force / effort force or effort distance / resistance distance FR / FE & MA = de / dr Just a number, no units. • Lever: IMA = Le/Lr (length of effort arm / length of the resistance arm) • Pulley: IMA = # ropes supporting the weight (1 for fixed, 2 for movable) • Wheel and Axle: IMA = rw/ra (radius of the wheel / by radius of the axis) • Inclined Plane: IMA = l/h (length of ramp / height of ramp) • Screw: IMA = l/h (distance all the way up threads / height of screw) • Wedge: IMA = l/h (length of wedge / height of wedge)

13. Forces, Waves, and Electricity Part 6 – Mechanical Advantage of Simple Machines • Mechanical Advantage Cheat • You could try and remember 16 different equations, or you could remember the following: • Always take the larger number and divide it by the smaller number

14. Forces, Waves, and Electricity Part 7 – Waves Transmit Energy • Waves carry energy • The frequency of a wave is how many waves pass in one second, given in Hertz (Hz) • Shorter wavelength (crest-to-crest distance) at the same speed means higher frequency. • High frequency and short wavelengths means more energy transmitted

15. Forces, Waves, and Electricity Part 8 – Wave Behavior • Reflection – Wave bounces off of something (echo and looking in the mirror) • Absorption – Wave energy is absorbed and changed into heat (light shining on black shirt) • Refraction – Wave changes speed and bends as it passes from one medium to another (pencil looks broken when placed half in a glass of water) • Diffraction – Wave bends as it passes around something (you can hear someone talking around the corner even though you can’t see them) • Interference – Two waves running over the top of each other (mixed radio stations or noise canceling headphones)

16. Forces, Waves, and Electricity Part 9 – Speed of Sound Waves • Sound is a mechanical wave, so it only works through a medium (does not work in a vacuum like space) • Sound moves faster in denser material, so the speed of sound is slow in air, fast in water, really fast in steel • Sound moves faster in hotter materials, so it is slower in cold air than hot air

17. Forces, Waves, and Electricity Part 10 – Electromagnetic Waves • Electromagnetic waves are caused by vibrations of electrons that cause both an electric force wave and a magnetic wave at right angles to each other. • EM waves can pass through a vacuum and they all move really fast (186,000 miles/second in a vacuum) • Big wavelengths mean small frequency and small energy, small wavelengths are high energy and high frequency. From low to high energy they are: Radio, microwave, infrared, visible light, ultraviolet, x-ray, gamma ray. Remember this by saying: “Real Men In Vegas Use X-Ray Glasses”

18. Forces, Waves, and Electricity Part 11 – Electromagnetism • Magnetism and electricity are the SAME fundamental force • Moving electrons (electricity) make a magnetic field (an electromagnet) • Moving a magnet near a conductor (wire) makes the electrons in it flow (a generator) • Electromagnets and permanent magnets are used in speakers, electric motors, generators, radios, televisions, etc… • Generators transform mechanical energy into electrical energy. Motors transform electrical energy into mechanical energy (common test question)

19. Forces, Waves, and Electricity KEY POINTS • Speed = distance divided by time • Acceleration = change in speed divide by time • Gravity makes things speed up (accelerate) and depends on how far apart they are and how much mass the two things have • Mass I how much matter an object contains and is the SAME for any object everywhere in the universe. • Waves transfer energy. Higher frequency and shorter wavelengths mean more energy • Sound travels faster through denser, hotter materials • Moving electrons make a magnetic field. Moving magnets make an electric field

20. Energy Transformations (15%-17%)

21. Energy Transformations Part 1 – Radioactive Decay Products • An atom with a really big nucleus may decay. • Small atoms that do not have a 1:1 ratio of neutrons and protons may decay. • Large atoms that do not have a 3:2 ratio of neutrons to protons may decay • Alpha Particle: 2 protons and 2 neutrons, low energy, ionizing, may be stopped by sheet of paper, same as He nucleus • Beta Particle: Electron given off when proton turns into Neutron, higher energy may be stopped by aluminum foil • Gamma Ray: Electromagnetic radiation given off when atom decays, very high energy, very hard to stop – 2 feet of concrete.

22. Energy Transformations Part 2 – Radioactive Half-Life • The Half-life of a radioactive isotope is how long it takes exactly HALF of it to decay into something else. • After 1 half-life, 50% of original sample left. • After 2 half-lives, 25% of original sample left. • After 3 half-lives, 12.5% of original sample left. • The half-life of C-14 is 5,720 years. If 25% of the C-14 is still in an old bone, the 2 half lives have passed and it is ~11,440 years old.

23. Energy Transformations Part 3 –Kinetic Theory • Explains how particles in matter behave 1. All matter is made of small particles (atoms, molecules and ions) 2. These particles are in constant random motion 3. The particles are colliding with each other and the walls of their container (think of thousands of tiny tennis balls flying around hitting each other)

24. Energy Transformations Part 4 –Particle Motion in States of Matter • Solid – definite shape and volume. Particles move only a little in place and never leave position (kids in their desks) • Liquid – indefinite shape but definite volume. Particles stay together in a group, but can change position (kids in the halls) • Gas – indefinite shape and indefinite volume. Particles are free to bounce around all over the place (kids at the playground)

25. Energy Transformations Part 5 – Energy in Phase Changes • It takes a lot of energy to melt or boil something. • If you add heat (Joules of energy) to an ice cube that is below freezing, it will heat up to 0oC THEN STOP WARMING UP until all of the ice is melted, then it will start warming again. All of the heat was going toward breaking the bonds between the particles. This is called the Heat of Fusion. • The same thing happens when you reach the boiling point, except that the energy it takes to change a liquid to a gas is called the Heat of vaporization. • If you go the other way (condense or freeze something) it must give off the same amount of heat.

26. Energy Transformations Part 6 –Phase Diagram

27. Energy Transformations Part 7 – Energy Transformation and Conservation • Energy is never made or lost (except in nuclear reactions), it just changes form. • Lighting a match changes mechanical and chemical energy into heat and light. • Cranking a generator to power a light bulb changes mechanical energy into electrical energy into heat and light. • Using a battery to power a motor changes chemical energy into electrical energy into mechanical energy.

28. Energy Transformations Part 8 – Conduction, Convection, and Radiation • HEAT is energy in Joules that can be passed from one thing to another in three ways. 1. Conduction – direct touching. Works best with solids. Vibrating particles of hot object speed up the particles of the cooler one it is touching (frying pan on stove) 2. Convection – works with gas and liquids. Heat added to bottom. Warm part rises, cool part sinks to get heated up too (boiling pot of water) 3. Radiation – works over a distance, best through gases or vacuum – infrared radiation transmits energy from hot object to cooler one (holding your hand near the stove to warm them)

29. Energy Transformations KEY POINTS • Half-life is the amount of time it takes for 50% of the atoms of a radioactive isotope to decay. After 2 half-lives, 75% have decayed. After 3 half-lives, 87.5% have decayed. • Solids have definite shape and volume and little particle movement • Liquids have indefinite shape and definite volume with higher energy particles. • Gases have indefinite shape and volume with freely moving particles • Thermal energy (heat) is measured in Joules and can move from warmer to cooler things by conduction, convection, or radiation

30. Structure and Properties of Matter (25%-27%)

31. Structure and Properties of Matter Part 1 –General Atomic Structure • Atoms contain protons and neutrons and are surrounded by a cloud of electrons in different energy levels. • The electrons have about 1/2000 the mass of each proton and neutron, so almost all of the mass of the atom is in the nucleus. Each proton and neutron has a mass of 1 AMU. • Atomic Mass = # of protons + # of neutrons • Atomic Number = # of protons AND determines which element an atom is (all C has exactly 6 protons, all U atoms have exactly 92 protons) • Protons are positive, neutrons neutral, electrons are negative.

32. Structure and Properties of Matter Part 2 –Structure of a Carbon-12 Atom Electron Cloud Proton (1+ charge) Neutron (no charge) Electron (1- charge) Nucleus

33. Structure and Properties of Matter Part 3 –Isotopes • Isotopes of an element have the same number of protons, but different masses • That means different numbers of neutrons! • C-14 has a mass of 14, but its atomic number is 6. Therefore, 14 – 6 means it has 8 neutrons. • C-12 has a mass of 12. 12 – 6 means 6 neutrons. • Chemically C-12 and C-14 act the same, but C-14 is radioactive and has more mass. They are both ISOTOPES of carbon.

34. Structure and Properties of Matter Part 4 –Reading the Periodic Table • You must be able to identify the symbol, atomic number, and atomic mass (or weight) for the first 20 elements on the periodic table

35. Structure and Properties of Matter Part 5 - Solutions • Solution: mixture that has the same composition, color, density and taste throughout. You don’t see dissolved sugar crystals because they are evenly mixed through the whole solution. • A solution has a solvent and a solute. The solute is dissolved in the solvent. The solvent is whatever there is the MOST of. • Solutions may be: • Liquid: salt water (water is the solvent, salt the solute) • Solid: steel (iron is the solvent, carbon the solute) • Gas: air (nitrogen is the solvent, oxygen the solute)

36. Structure and Properties of Matter KEY POINTS • Atomic Number is the number of protons • Atomic Mass is the number of protons + neutrons • Atoms with the same number of protons but different numbers of neutrons are ISOTOPES of the same element • Protons are positive, neutrons neutral, and electrons are negative. • The protons and neutrons are in the nucleus and the electrons are in a cloud around the nucleus. • Almost all of the mass of the atom is in the nucleus • In a solution, the solvent is the part of the mixture there is the MOST of and the solute is the part there is the least of. Remember this because solute is the smaller word!

37. Cells & Heredity (15%-17%)

38. Cells and Heredity Part 1 – Intro Cells • All living things are made up of cell or cell parts. • Leeuwenhoek discovered cells after he invented the microscope. • Two main types of cells: prokaryotic (no nucleus) and eukaryotic (have a nucleus).

39. Cells and Heredity Part 2 – Cell Parts • Cell parts and functions: • Cell membrane determines what can enter and leave the cell. • Cell wall surrounds the cell membrane in plant cells and gives the cell structure. • Nucleus is the control center of the cell. • Cytoplasm is where the other cell parts are suspended and where most of the chemical reactions of the cell take place.

40. Cells and Heredity Part 3 – Organelles • Ribosomes are where proteins are made. • Vacuoles store food, water, and wastes. • Endoplasmic reticulum transports proteins and other substances throughout the cell. • Golgi apparatus packages proteins for transport. • Mitochondria provide energy for the cell. • Cell parts are called organelles and they all work together to maintain homeostasis in the cell. Homeostasis refers to maintaining a balance in life functions so that the cell is healthy.

41. Cells and Heredity Part 4 – Cell Transport • There are two main ways cells get substances into and out of cells. • Passive transport requires no cell energy (diffusion and osmosis). • Active transport requires the use of cell energy (endocytosis and exocytosis).

42. Cells and Heredity Part 5 – Organic Molecules • Four main types of macromolecules: • Carbohydrates – used mainly for energy. Sugars, starches, and cellulose. • Lipids – make up cell membranes. Fats, oils, and waxes. • Proteins – building material. • Nucleic acids – DNA and RNA.

43. Cells and Heredity Part 6 – Classification • There are six kingdoms of living things: • Eubacteria – unicellular, prokaryotic, mainly heterotrophic (have to take in food). “Typical” bacteria. • Archaebacteria – bacteria adapted to extreme environments. Ice, hot springs, etc. • Protista – some are unicellular and some are multicellular, all are eukaryotic, some are autotrophic (make their own food), some are heterotrophic, and some are both. • Fungi – all are multicellular (except yeast), eukaryotic, heterotrophic. • Plantae – multicellular, eukaryotic, autotrophic. • Animalia – multicellular, eukaryotic, heterotrophic.

44. Cells and Heredity Part 6 – Classification • Seven levels of classification: • Kingdom All living things are placed into • Phylum one of the six kingdoms based • Class on their characteristics. Once • Order placed, they are then further • Family classified into the other levels. • Genus The species level refers to one • Species particular organism.

45. Cells and Heredity Part 7 – DNA • DNA transmits hereditary information from generation to generation. • DNA tells cells what kind of proteins to make. • When cells reproduce, the DNA code must be copied exactly. Incorrect copying can result in a mutation. • Proteins are made in the cytoplasm at the ribosomes. DNA cannot leave the nucleus. DNA makes a copy of itself, called RNA, that can leave the nucleus. RNA carries the genetic code of the DNA out to the ribosomes. • DNA is shaped like a twisted ladder. This shape is called a double helix.

46. Cells and Heredity Part 8 – History of DNA • Gregor Mendel was an Austrian monk. • Mendel discovered how traits, in the form of genes (small segments of the DNA molecule), are transferred from one generation to the next. • Traits include such things as height, hair color, eye color, and skin color. • Mendel came up with 3 laws of genetics.

47. Cells and Heredity Part 9 – Mendel’s Laws • Dominance and recessiveness. Some traits are “stronger” than others. • Law of segregation. The two genes for each trait segregate (separate) during sex cell formation, so each sex cell has only one gene for a trait. • Law of independent assortment. The inheritance of one trait does not influence the inheritance of another trait.

48. Cells and Heredity Part 10 – Punnetts • A Punnett square can be used to predict the expected outcome of a genetic cross between two individuals. • Capital letters represent dominant traits and small letters represent recessive traits. • In this example, brown eyes (B) are dominant to blue eyes (b). An individual with one gene for brown eyes and one gene for blue eyes (on the side of the box) has been crossed with an individual with two genes for blue eyes (on top of box). 50% of the offspring are Bb (heterozygous) and have brown eyes; 50% of the offspring are bb (homozygous recessive) and have blue eyes. b b B b

49. Cells and Heredity Part 11 – Genetic Crosses • There are many types of genetic crosses: • Sex linked (carried on the x chromosome); • Sex influenced (depends on sex of person); • Codominance (shared dominance); • Incomplete dominance (mixed traits); • Polygenic (more than one gene determines a trait).

50. Cells and Heredity Part 12 – Sex Determination • Humans have 23 pairs of chromosomes. • One pair is the sex chromosomes. • Males have one x and one y chromosome. • Females have two x chromosomes. • If a y sperm fertilizes an x egg, the baby will be a boy. • If an x sperm fertilizes an x egg, the baby will be a girl.