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Matter commonly exists in four different phases: ◦ Gas –matter has neither definite volume nor definite shape ◦ Solid –matter has both definite shape and definite volume ◦ Liquid – matter has a definite volume but not a definite shape ◦ Plasma-extremely hot, electrically charged, gas like substance The Kinetic Theory of Matter states three things: 1. The universe is made of invisible, tiny particles with empty space between them. 2. All of these particles move all the time. This is where the “kinetic” part comes from 3. The motion of the particles is random. All particles of matte are always in motion Heat Energy is the energy that causes the particles of a substance to move faster ◦ Higher temp= particles moving faster ◦ Lower temp= particles moving slower Temperature is the measure of the average energy of motion of all the particles of a substance The phase change from a liquid to a gas is called vaporization The phase change from a gas to a liquid is called condensation When a substance changes from a solid to a gas without going to liquid first is called sublimation Gas particles become solid without going through the liquid state is called deposition During phase change, the mass of a substance stays constant but its volume may change Most solids and liquids increase as they heat up an effect called thermal expansion Conductivity refers to a substance’s ability to transfer heat energy or electrical energy from one place to another An object with low conductivity resists the flow of hear or electricity Matter has both physical and chemical properties Physical properties include mass, volume, and density Chemical Properties are the qualities of a substance that describe what will happen when the substances interacts with another substance Matter can undergo physical and chemical change as well A chemical change, a substance turns into one or more new substances that have different properties than the original substance or substances In a chemical reaction the original substances that change are called reactants the new substances that form are called the products A large portion of chemical reactions produce heat or absorb it. A chemical reaction that produces heat is called exothermic ◦ Gets hot A chemical reaction the absorbs heat is called endothermic ◦ Gets cold During both chemical and physical changes, there is no overall increase or decrease in the amount of matter that is changing. This is known as the law of conservation of matter An element is a substance that cannot be broken down into any simpler substance by physical or chemical means ◦ There are more then 100 elements The elements are arranged by atomic number (the number of protons in an atom’s nucleus) The atomic mass is also listed for each element. ( the combined mass of two particles; protons and neutrons) An atom has three subatomic particles with different changes ◦ Proton= positive ◦ electron=negative ◦ Neutron =no charge There are three main groups of elements on the periodic table Metals ◦ Conduct heat and electricity ◦ Malleable ◦ All are solid at room temperature except Mercury ◦ Nonmetals Poor conductors Not malleable Britle Metalloids ◦ Have both properties of metals and nonmetals but they are neither one nor the other When two or more atoms bond, they form a molecule with properties different from either of the original atoms Chemical formula tells you the types and numbers of each atoms in single molecule. If the molecule contains atoms of two or more different elements it is a compound When speed and direction changes, the object undergoes acceleration ◦ Measured in meters per second squared, m/s² Speed and Velocity are NOT the same thing Speed is the measure of how fast an object is moving Velocity includes speed and direction of an object ◦ Car traveling west at 60km/hr A force is a push or a pull A contact force must touch an object to change its speed and direction ◦ Example is friction – slows down objects due to particles touching each other Normal Force is the force exerted by an object to balance an outside force acting on it ◦ Example – standing on the ground you exert a force on the ground and the ground exerts a force back on you. Noncontact Force – can act on objects from a distance ◦ Example- gravity is a force that pulls two objects with mass toward one another The force of gravity depends on two things: mass and distance from each other Newton’s first law of motion states that an object in motion will continue in motion and an object at rest will stay at rest unless acted on by an outside force The objects resistance to a change in its motion is called inertia. Newton’s first law of motion is called the law of inertia ◦ The more mass an object has the greater its inertia Newton’s second law of motion states the acceleration of an object is related to the new force acting on it and to the object’s mass. F= mass x acceleration or F=ma Force is measured in Newton ◦ N=kg x m/s² Many forces may act on an object at any given time. When you add up all the forces, you get the net force When you add up all the forces and you get 0 Newton it is said to be balanced When it is anything other than 0 Newton it is unbalanced and accelerating Newton’s third law of motion states that forces come in pairs: For every action there is a reaction that is equal in magnitude (size) but in opposite direction ◦ Remember that equal and opposite forces act on different objects, normally with different masses Geologists classify rocks into three groups: ◦ Sedimentary, igneous, and metamorphic Igneous rock forms when molten rock cools and hardens ◦ Magma is molten rock beneath the surface ◦ Lava is molten rock on the surface Sedimentary rocks are formed from sediments ◦ made of Bits of rock, parts of animals Metamorphic Rocks form when existing rocks are exposed to intense heat, pressure, or both In 1915, the German scientist Alfred Wegner proposed the theory of continental drift The theory states that all the Earth’s landmasses were once part of a giant continent that broke apart The pieces drifted over the surface of the Earth In the 1960s geologic observations provided evidence that the ocean floor was spreading outward from a series of underwater mountain chains called midocean ridges The Earth’s crust rides on top of giant slabs of rock called plates ◦ Together, the crust and the plates make up the lithosphere, the solid surface of the earth Geologists believe that huge currents in the mantle provide the force that causes the plates to move. The movement of matter due to differences in temperature is called convection There are three type of plate boundaries: ◦ Transform, divergent, and convergent At a transform fault boundary, two plates grind past each other without creating or destroying the lithosphere At a divergent plate boundary, a section of oceanic lithosphere splits apart. The splitting forms two plates that pull away from each other Divergent boundaries make new crust Convergent plate boundaries occurs when two tectonic plates move toward one another Create: continental mountains, volcanoes, deep ocean trenches There are three types of convergent boundaries ◦ Oceanic-continental ◦ Continental- continental ◦ Oceanic-oceanic The earth is always experiencing two types of motion ◦ It rotates on its axis ◦ It revolves around the sun The Earth’s seasons result from a combination of two factors: the Earth’s revolution around the sun and the Earth’s axial tilt Just as gravity governs the orbits of objects around the Sun, gravity also governs the Moon’s orbit around the Earth. Gravity is used to predict the phases of the moon. The phase of the moon refers to the moon’s appearance in the sky It takes the moon about 28 days to orbit the Earth, also known as a lunar month The same side of the moon always faces the earth. During a solar eclipse, the moon is directly between the Earth and the Sun ◦ The moon blocks the sun’s light and the moon’s shadow falls directly on the earth During a Lunar Eclipse, the sun is directly between the Moon and the Sun The moon’s gravity causes the Earth’s ocean tides The moon tugs more strongly on the water closest to it There are two different types of tides: spring and neap tides Spring tides occur when the moon is full or new ◦ At this time the sun, moon and earth are in a line ◦ The sun and moon work together to create tides that are higher than normal Neap tides occur when the moon is half full ◦ At these times, the sun is at a right angle to a line between the earth and the moon ◦ The sun and the moon do not work with one another Evolution is also about change, but its change on a large scale. ◦ Individuals don’t evolve ◦ A large group of organisms can evolve It can take tens or hundreds of generations for a species to change in visible ways ◦ Because it takes so long for an organism to evolve scientists rarely see it happen Its easy to see variation in the individuals of a population ◦ Just like in humans, unless there is a twin, organisms are not identical One source of variation in a species come from the process of sexual reproduction ◦ The offspring are slightly different from the parent Mutation is also another way that an organisms vary from one to another. A mutation is a change in an organism’s genetic makeup Many mutations harm an organism’s ability to survive, while others have no effect on the individual organism ◦ Sometimes mutations give organisms an advantage over organisms of the same species A trait that increases the chances that an organism will survive to reproduce is called an adaptation ◦ The adaptation is more than likely going to be passed on to one or more of the offspring In artificial selection, humans breed plants or animals that have certain traits in the hopes that their offspring will also have those traits ◦ Over thousands of years humans have bred dogs to have specific traits In natural selection, pressures within the environment favor the survival of individuals within certain traits over individuals with certain traits with individuals that lack those traits The term natural selection makes it sound as if someone or something is choosing which organisms will live and which ones will die Natural selection means that pressures within the environment favor the survival of individuals with certain traits over individuals who lack those traits Over thousands or million of years natural selection can make new species out of existing species. This process is called speciation. ◦ Darwin and the finches Continental drift is a major factor that drives biological evolution ◦ The camel from Africa and the llama are descendants of a common ancestor that lived before these two continents split apart Other geologic processes are a driving force for evolution. Major earthquakes and volcanic activity can produce new mountains ranges that separate groups of the same species. Sudden catastrophes have also had a major impact on evolution. ◦ Scientists widely accept the theory that Earth’s collision 65 million years ago with a large asteroid or comet contributed to the extinction of the dinosaurs Energy is the ability to make a force that moves matter. ◦ Energy is the capacity to do work Work is done when a force is applied to matter, and the matter moves in the direction that the force acts. The unit for work is the Newton The unit for energy is the Joule Energy can be transformed from one form to another. Energy cannot be created or destroyed but it is transformed from one form to another The law of conservation of energy states that energy cannot be created or destroyed bu only change form. Heredity refers to the passing of traits from parents to offspring. Genes control the traits that appear in those offspring. When organisms reproduce, they give genes to their offspring, and those genes cause traits to appear. Each gene is a small piece of a long molecule called DNA In the reproductive process DNA arranges itself into structures called chromosomes Sexual reproduction 2 parents Male contributes sperm Female contributes eggs Sperm and eggs cells are called gametes or sex cells ◦ Produce sex cells through a process known as Meiosis ◦ ◦ ◦ ◦ End result is four sex cells with half the chromosomes of the original cell The process by which a sperm and an egg cell join is called fertilization In fertilization, half of the male’s chromosomes join with half of the female’s chromosomes to make one complete set of chromosomes ◦ The offspring's set of genes is different from either of the parent’s set of genes Asexual Reproduction ◦ ◦ ◦ ◦ One parent Reproduces without using sex cells No fertilization Offspring are identical to parent Many single celled organisms reproduce by a form of mitosis ◦ A cell duplicates its chromosomes and divides into two cells Each cell is an exact copy of the parent The outside expression of a gene is called the phenotype ◦ Eye color ◦ Hair color Humans have two copies of each gene, called alleles ◦ One from the mother ◦ One from the father When scientists determine which two alleles a person has they are determining the person’s genotype ◦ Hh ◦ HH ◦ hh A dominate allele cause the expression of each trait. A dominate allele masks the expression of recessive alleles ◦ Upper case represents the dominate allele H ◦ Lower case represents the recessive allele h If a person has two identical alleles, the person is homozygous for a trait – HH or hh If a person has two different alleles, that person is heterozygous for a trait - Hh If you know the genotypes of people who are about to have a baby, you can use a Punnett Square to predict the probability that their children will inherit their alleles A Punnett Square shows all of the possible combinations of alleles that children can inherit when two people produce an offspring.
