# IS 352 Test 1

 What are the 9 processes of Science? 1. Observing2. Measuring3. Classifying 4. Inferring5. Predicting6. Experimenting7. Hypothesizing 8. Explaining9. Communicating Observing Activity The candle was described qualitatively and quantitatively before it was lit, during burning and after burning. Measuring Activity Ice cubes were placed in a beaker. Observations were made and recorded. The height of the water in the beaker was measured before melting and after melting. The height did not change because the ice displaced the water and when it melted it filled the space up. Classifying Activity Buttons and "wild things" were classified as a binary classification system and a multi-stage classification system. Inferring Activity Why does moisture collect on a beaker of ice water? Because room temperature is warmer than the ice water and causes condensation. The condensation comes from the moisture in the air. We can show that the moisture does not come from inside the glass by adding food coloring to the water. Hypothesizing Activity The warmer water dissolved the Alka-Seltzer tablet faster than cooler water. The manipulated variable was the water temp., the responding variable was the time it took for the tablet to dissolve, and the control variables were the size of the tablet, the brand of the tablet, the water, the plastic cups, and the amount of water. Predicting Activity What's in a bag of M&M's? Predict the number of M&M's in a bag, the number of each color, and the most and least common colors. Compare data with the rest of the class groups and chart the data. On average there were more orange M&M's and the least amount were the red M&M's. Communicating Activity Tanagrams - one group member secretly made a design and tried to guide the other group members only with words on how to create the design. Not easy. Matter The stuff that everything is made of, or anything that has mass and volume Mass The amount of matter in an object, expressed in grams Weight The measure of the force exerted on an object by the pull of the Earth's gravity, expressed in Newtons Volume the amount of space taken up by an object, defined by l x w x h, or mL Pure Substances constant composition with a specific set of properties Elements basic building blocks of matter Compound 2 or more elements Mixtures 2 or more pure substances where each substance will keep its own identity, does not form a new substance. i.e. sweet tea Difference between physical and chemical properties and change: Physical Properties - characteristics of an object that can be observed or measured, can be changed without changing the object itselfChemical Properties - chemical changes the ability of matter to change into a new substance that has different properties. i.e. sterling silver -> (oxidation) -> black color (petina) 4 Signs that can tell you a Chemical Change has taken place: 1. gas is produced - fizzing2. color change - rust3. temperature change4. produces light Difference between heterogeneous and homogeneous mixtures: Homogeneous mixture - well mixed, appears to be uniform but proportions can vary. i.e. sugar in a glass of teaHeterogeneous mixture - not uniform, unevenly mixed 3 Phases of Matter and difference in physical properties of each: Liquid - definite volume and indefinite shapeSolid - definite volume and definite shapeGas - indefinite volume and indefinite shape Burning a Candle Activity The wick and wax work together as a system. The wax is the fuel and the wick transports the fuel to the flame. Without oxygen the flame cannot burn. The Distinguishing Properties of Common White Powders Each substance (granulate sugar, table salt, baking soda & cornstarch) behave differently when mixed with the various substances (water, iodine & vinegar). The biggest reaction came from mixing iodine with cornstarch. The cornstarch hardened and turned black. the other came when mixing vinegar and baking soda, which produces a gas evident from fizzing. Both of these are chemical reactions. What are the properties of Oobleck? Liquid or Solid? It doesn't have a definite shape, so it can't be a solid. It has a definite volume and no definite shape so it fits the definition of a liquid. Changes of State of Water - 6 changes + Heat NRG Solid -> Liquid = Melting Liquid -> Gas = Evaporation Solid -> Gas = Sublimation- Heat NRG Gas -> Liquid = Condensation Liquid -> Solid = Freezing Gas -> Solid = Deposition Latent Heat The energy absorbed or released during a change of state. Calories the amount of heat it take to raise 1 gram of water 1 degree Celsius Dew point temperature the temperature at which the air must be cooled in order for condensation to occur Condensation change of state from a gas to a liquid with a loss of heat energy Humidity description of the amount of water vapor in the air Saturation the maximum possible amount of water vapor the air can hold at a given temperature and pressure Meniscus in a graduated cylinder the meniscus is read at the bottom of the curve What is condensation and how does it occur? Condensation is a change of state when a gas turns into a liquid with a loss of heat energy. The ice cools the sides of the cup which cools the warmer air that contains the water vapor very close to the outside of the cup. Water vapor gathers on the outside of the cup as condensation. What is the temperature at which condensation takes place? Condensation first started showing on the cup at 5 degrees Celsius, when the temperature had dropped 19 degrees. 3 Subatomic Particles Proton - inside nucleus, + charge, atomic #, identification of element depends on the number of protonsElectron - outside nucleus, - charge, # always = # protons, influence chemical reactionNeutron - inside nucleus, no charge Atomic Number the order of an element in Mendeleyev's table of the elements; equal to the number of protons in the nucleus Atomic Mass Number (Atomic Weight) Protons + Neutron = Atomic Mass Molecule 2 or more atoms are combined, smallest unit of a compound Organization of the Periodic Table - Names of Groups Rows: periods, there are 7Columns: family - there are 18, they react in the same wayGroup 1: Alkali Metal - very reactive, hardly find in natureGroup 2: Alkaline Earth MetalsGroup 3 - 12: Transition ElementsGroup 13 - 16: BCNOGroup 17: Halogens - non-metals, 5 elements, combine with alkali metals for form saltsGroup 18: Noble Gases - found in Earth's atmosphere, colorless and odorlessRed Symbols: GasesSolid Black Symbols: SolidsBlue Symbols: liquids at room temperatureOutlined: Synthetic Difference between a metal, nonmetal and metalloid: Metal (left hand side):Silver gray in colorMalleable Shiny metallic lusterCan be magneticGood conductors of heat and electricityHigh densitiesNon-Metals (right hand side):Not shiny TransparentBrittle - will shatterNot magneticNot conductors of heat or electricityLow densitySome gases at room temp., some liquids & some solidsMetalloid (semi-conductors in red outline):SolidsDull or shinyMalleable or brittleDensity variesConduct heat and electricity better than non-metals but not as good as metalsHas properties of metal and non-metals Which 2 elements are liquids at room temperature? Bromine and mercury Chemical bond an attractive force that holds atoms together in a compound Spheres of Hydration The sphere of water molecules around each dissolved ion. Cohesion attraction of like molecules Adhesion attraction of dissimilar molecules Chemical Reaction a change in matter in which different chemical substances are created by breaking or forming chemical bonds Hydrophilic Water-loving, readily bonds with water Hydrophobic does not like water, i.e. oil Endothermic chemical reaction occurring or formed with absorption of heat Exothermic chemical reaction occurring or formed with the release of heat 4 Types of Chemical Bonds Covalent - formed by sharing a pair of electrons, generally, non-metallic elements Polar - unequal sharing Non-polar - atoms share electrons equallyIonic - atoms transfer electrons, in general a metal reacts with 1 or more nonmetalsMetallic - formed between 2 or more metals, give electrical conductivityHydrogen - atoms share electrons in a water molecule Unusual Properties of Water 1. The only substance found naturally on Earth in all 3 states2. Temperature scales all based on water3. Universal solvent4. Density5. Cohesion 6. Polarity of water - water attracts other polar molecules like sugar which is hydrophilic Balance Chemical Equations Practice Law of Conservation of Mass Matter is neither created nor destroyed during a chemical reaction Oxidation-Reduction Reaction - Redox An oxidizing chemical change where an element's electron loss is accompanied by a simultaneous electron gain. Generalized form for Each of the Subclasses or Redox Reactions 1. Combination reaction: x + y -> xy2. Decomposition reaction: xy -> x + y3. Replacement reaction: xy + z -> xz + y Chemical Heating Activity The vinegar reacted with the steel wool and produced heat energy. Evidence of a chemical reaction: produced rust, heat, and moisture Breakdown Activity Change hydrogen peroxide into water and oxygen with the aid of a potatoTiny bubbles form and rise to the topThe potato releases oxygen to form bubblesDecomposition Reaction: H2O2 >> 2H2O(l) + O2 (g)The potato contains enzymes catalase that speeds up the reaction. Exothermic Exercise Mix yeast with hydrogen peroxide. The yeast reacted to the hydrogen peroxide and heat energy was released raising the temperature of the mixture. Evidence of a chemical reaction: heat is produced, bubbles produced Endothermic Exercise The Epsom salt absorbed the water's natural heat energy to split apart the magnesium and sulphate therefore making the water cooler.MgSO4 + H2O Bill Nye - Chemical Reactions Everything is mad of chemicalsChemicals react to make new chemicalsElectrons hook togetherChemicals react with chemicals in the air and give off heatWater is the most important chemical 92 pure elementsAlfred Nobel - Swedish chemist who invented dynamite Authorkcooper ID71508 Card SetIS 352 Test 1 DescriptionTAMU-Commerce IS 352 Test 1 Updated2011-03-08T19:36:51Z Show Answers