Notes Ch1-4 - Summary Conceptual Chemistry PDF

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Chapter 1: About Science Science is a way of Understanding the Natural World Matter is made of atoms, and atoms form into larger structures called molecules. Science: the product of observations, common sense, rational thinking, experimentation, and sometimes brilliant insights.  Modern science began when people first became skeptical of their observations and explanations. o Learning that our ideas are false is useful information. It prompts us to double check our thinking o The more experiments we conduct and more times we refine our explanations, the closer we get to understanding the actual workings of nature. The Wheel of Scientific Inquiry  Broad Question  Document Expectations  Make Observations  Confirm Results  Narrow the Focus  Reflect on Findings  Learn what is Known  Communicate with Others o Measuring your weight on a broken scale is an example of a flawed procedure  Perform Experiments  Ask specific Questions  Communications with Others  Reflect on the Findings The Discovery of the Buckyball 

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Harry Kroto, Rick Smalley and Bob Curl. o Harry Kroto's interests were in identifying the composition of interstellar dust. The dust is found in the cast distances between stars. o It is possible to identify materials in space by studying the light they emit or absorb.  Spectoral patterns from our sun tell us that the sun is made mostly of hydrogen and helium.  Kroto understood that interstellar dust is createdd by stars, especially those producing carbon.  Broad Question:  Document Expectations Technology is Applied Science  Science is concerned with gathering knowledge about the natural world.  When we apply this knowledge for practical purposes, we have technology. o New technology can be of assistance to scientists in conducting their research. o Technology arises from science, but technology also supports progress in science. o For every cause, there is an effect. It can be wither good or bad. o Humans who use the technology are the ones who need to see that there is responsibility. o The promise of technology is a cleaner and healthier world. Wise applications of technology can lead to a better world Risk Assessment  When the benefits of a technological innovation are seen to outweigh it's risks, the technology is accepted and applied. o Ex. X-rays, good things and bad things about it. it is used sparingly, but has great benefits. o Aspirin is good for adults, but harmful for children. We are Still Learning about the Natural World  Science is a work in progress. The understandings we have one year will not necessarily be the understanding we have the next year. Fact: Something agreed upon by competent observers as being true.  Today we recognize the fact that the universe is expanding and evolving.  A hypothesis is a suggested explanation for an observable phenomenon.

Scientific Hypothesis: when a hypothesis can be tested through experiments. o If the hypothesis fails one test, it is taken as false. Scientific Law: when a hypothesis has been tested and supported by experimental data over and over again and has not been contradicted. Scientific Theory: an observable phenomenon. Chemistry is Integrated to our lives Chemistry: is the study of matter and the transformation it can undergo Matter: anything that has mass and occupies space. Basic research: research is any activity whose purpose is the discovery of new knowledge.  Applied research: Focuses on the development of useful applications of the knowledge laid down by basic research.  Any measurement of a physical quantity must include a number followed by a unit that tells us not only what was measured but also the scale of the measurement.

CHAPTER 2: PARTICLES OF MATTER Atoms: Very small fundamental units o Single grain of sand: 125,000,000,000,000,000,000 = 1.25 x 10^20 Molecules: Atoms that link together to form larger but still incredibly small units of matter o Scientific notation: 1 x 10^24  Astronomical Level - Earth, atmosphere  Macroscopic Level - matter is large enough to be seen, measured, or handled.  Microscopic Level - Blood cells, bacterium, virus (so fine that it can only be seen through a microscope.)  Submicroscopic Level - Molecules and atoms (important focus of chemistry.) Discovering the Atom  Aristotle described the composition and behavior of matter in terms of HOT, COLD, MOIST, DRY. o Think of pottery: when it is made it is wet, and the clay changes to ceramic because the heat of the fire drives out the moist quality of the wet clay and replaces it with the dry quality of the ceramic. o Atom - (greek) A tomos means "not cut". Or "that which is indivisible" Alchemy: A field of study concerned primarily with finding potions that would produce gold or confer immorality. o Aristotle believed that he could turn lead into gold by altering the proportions of the 4 basic qualities. o Alchemists learned much about the behavior of many chemicals and developed many useful laboratory techniques.  Lavoisier further hypothesized that an.. Element: is any material made of a fundamental substance that cannot be broken down into anything else. o Through experimentation, he was able to transform water in two different substances--Hydrogen and oxygen. (water is not an element, Aristotle was wrong) Dalton wrote Claims he assumed to be true based on experimental evidence. 1. Each element consists of indivisible, minute particles called atoms. 2. Atoms can be neither created nor destroyed in chemical reactions 3. All atoms of a given element are identical 4. Atoms of different elements have different masses.  Mendeleev's chart o Elements were listed in horozontal rows in order of increasing mass. Mass is How Much, and Volume is How Spacious Mass: is the quantitative measure of how much matter a material object contains.  The greater the mass of an object, the greater the amount of matter in it.  Mass is also a measure of an objects Inertia Inertia: the resistance the object has to any change in its motion. o A cement truck has a lot of mass (inertia) which is why it requires a powerful engine to get it moving and powerful breaks to cause it to come to a stop.  Standard unit of mass is a Kilogram  Since mass is simply a measure of the amount of matter in a sample, which is a function of how many atoms the sample contains, the mass of an object remains the same no matter where it is located. o A kilogram gold bar has the same mass on earth, the moon, and floating "weightless" in space. It is because it contains the same number of atoms in each location. Weight: the gravitational force exerted on an object dsby the most massive nearby body, such as earth.  The weight of an object depends upon the location.  It is customary in science to measure matter by its mass rather than its weight. Volume: The amount of space a material object occupies is its volume. Density is the Ratio of Mass to Volume  Th relationship between an objects mass and the amount of space it occupies is the objects density Density: The amount of mass contained in a sample divided by the volume of the sample. o Block of lead has more mass squeezed into its volume than a same sized block of aluminum. The lead is therefor more dense. o Density = Mass/Volume  Gas densities are much more affected by pressure and temperature than are the densities of solids and liquids.

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With an increase in pressure, gas molecules are squeezed closer together. (less volume, same mass) o Density of the air inside a divers breathing tank is much greater than the density of air at normal atmospheric pressure. o Increase in temperature, gas molecules move faster and thus have a tendency to push outward, occupying greater volume. o Hot air is less dense than cold air, which is why hot air rises. Energy is the Mover of Matter  Matter is substance, and energy is that which can move substance. Energy: the capacity to do work  If something has energy, it can do work on something else -it can exert a force and move something else.  We witness the effects of energy Potential Energy: stored energy that has "potential" for doing work o A rock at the top of a hill has the potential energy due to the force of gravity Kinetic Energy: The energy of motion o The faster a body moves, the more kinetic energy it has and therefore the more work it can do. Manipulating an Algebraic Equation  Density X volume = mass  Mass/Density = volume Temperature is a Measure of how Hot - Heat it is not  Atoms and molecules that form matter are in constant motion. o These particles possess kinetic energy o The everage kinetic energy is directly related to a property you can sense: how hot something is.  Striking a penny makes it warmer because the blow of the hammer causes its atoms to jostle faster, increasing the kinetic energy. Temperature: Tells us how warm or cold an object is relative to some standard. o All materials expand when their temperature is raised and contract when it is lowered. o Temperature measures the average kinetic energy of molecules Thermometer: Exploits this characteristic of matter. Measuring temperature by means of the expansion and contraction of a liquid, usually mercury or colored alcohol.  Celsius thermometer the number 0 is when pure water freezes, and 100 us to when water boild.  Fahrenheit is assigned to 0 of a mixture of snow, and 100 to the body temperature of a human Absolute Zero: The temperature at which the particles of a substance have absolutely no kinetic energy to give up.  It is important to understand that temperature is a measure of the average amount of energy in a substance, not the total amount of energy. o Energy in a swimming pool full of boiling water is much more than the total energy in a cupful of boiling water, even if both are the same temperature. Heat: Energy that flows from a higher-temperature object to a lower temperature object. o Heat is a form of energy, that is why a hot stove will burn you and a warm stove wont. The Phase of a Material Depends on the Motion of its Particles Solid: occupies a constant amount of space and does not readily deform upon the application of pressure. (definite volume and definite shape) Liquid: occupies a constant amount of space (definite volume, indefinite shape) Gas: Diffuse, having neither a definite volume, nor a definite shape. o Even through gas particles move fast, they take a long time to get across the room.  On the submicroscopic level, the solid, liquid, and the gaseous phases are distinguished by the extent of interaction between the submicroscopic particles (the atoms or molecules) Familiar Terms are Used to Describe Phase Changes Melting: the process by which a solid transforms into a liquid o Once the particles of the solid heat up it is difficult for it to hold together because they "jump" around. That is why it melts. Freezing: A liquid can be changed to a solid by the removal of heat. o Particles begin to move slowly and attract the forces between the particles to hold firm. Evaporation: A liquid can be heated so that it becomes a gas

Gas Laws Describe the Behavior of Gasses Boyle's Law: Pressure and Volume o When the density of gas is doubled, the pressure is doubled o When the volume of gas is decreased, the density and pressure are increased  Charles Law: Volume and Temperature o Volume of a gas decreased as its temperature decreases. o Volume of a gas decreases as its tempurature decreases. o The volume and abolute temperature of a gas are directly proportional. (when one gets bigger, the other one does also)  Avogadro's Law: Volume and Number of Particles o He hypothesized that the volume of a gas is a function of the number of gas particles it contains. (as the number of gas particles increases, so does the volume, assuming a constant pressure and temperature.) o Like blowing an air in bag, the more air you put into it the more the bag will expand  The ideal gas law and the kinetic molecular theory o The properties of a gas can be described by four interrelated quantities: pressure, volume, temperature, and number of particles. Kinetic Molecular Theory: 1. A gas consists of tiny particles, either atoms of molecules or both. 2. Gas particles are in constant random motion, colliding with one another and with the walls of their container 3. The impacts of gas particles on the walls of the container produce a jittery force that appears as a steady push against the inner surface. This pushing force provides the pressure of the enclosed gas. 4. Deviations from gas laws arise primarily because of the interactions occurring among gas particles and because gas particles are not infinitely small 5. The average kinetic energy (energy due to motion) of the gas particles is directly proportional to the temperature of the gas. 

Chapter 3: Elements of Chemistry Matter has Physical and Chemical Physical Properties: properties that describe the look or feel of a substance, such as color, hardness, density, texture, and phase. o Every substance has its own set of characteristics physical properties that we can use to identify that substance. o The physical properties of a substance can change when conditions change, but does not mean that a new substance is created. o Does not change chemical property o When heated the atoms become spaced farther apart, but the substance is still made of the same thing Chemical Properties: those that characterize the ability of a substance to react with other substances or to transform from one substance to another.  During a chemical change, there is a change in the way the atoms are chemically bonded to one another. Chemical Bond: the force of attraction between two atoms that holds them together in a compound. Chemical Change: any change in a substance that involves a rearrangement of the way atoms are bonded.  An energy of a current is sufficient to pull bonded atoms away from each other. Loose atoms then bond with different atoms, resulting in a new molecule. Reacting: material undergoing a chemical change  Chemical change = Chemical reaction Chemical Reaction: new materials are formed by a change in the way atoms are bonded together.  During a chemical reaction, new materials are formed by a change in the way atoms are bonded together. Distinguishing Physical and Chemical Changes can be Difficult  After a physical change. The molecules are the same as the ones you started with.  Physical change in appearance and restoring the original conditions of a substance are physical changes.  The rusting of iron is a chemical change, iron is moldable that can be built into cars is a physical change.  New bonds represent a chemical change, and the difference in positions are a physical change.  Growing is a result of chemical change Elements are made of Atoms  The great variety of substances results from the many ways a few kinds of atoms can be combined  Alphabets and colors are like atoms, only a few kinds of atoms combine in different ways to produce all substances. Elements: any material consisting of only one type of atom Periodic Table: Elements organized in a chart Atomic symbol: Letters of a word associated with that element.  Only the first letter of an atomic symbol is capitalized. Unless it is a combination of two elements. CO  Element is used in reference to macroscopic/microscopic level  Atom is used in reference to submicroscopic Elemental Formula: Number of atoms that arrange themselves in a unit of an element.  Elements are organized in the table based upon their physical and chemical properties. Matter can be classified as pure or impure Solution: all components are in the same phase Suspension: forms when the particles of a substance are finely mixed but not dissolved. (blood) The Advent of Nanotechnology  Nanotechnology generally concerns the manipulations of objects from 1 to 100 nanometers in scale. Scanning Probe Microscope: detects and characterizes the surface atoms of materials by way of an ultrathin probe tip.

Chapter 4: Subatomic Particles Physical and Conceptual Models Atoms are so small that the number of them in a baseball is roughly equal to the number of ping pong balls that could fit inside a hollow sphere as big as earth.  We can never see atoms in a visual sense o Because light travels in waves, and atoms are smaller than the wave leangths of visible light. o Any object that is smaller than the wavelengths of light will remain invisible.  Atoms are made mostly of empty space. Physical Model: A model that replicates the object at a more convenient scale o An example would be to show a model of a microorganism that a student will use to study. Conceptual model: a representation of a system that helps us predict how the system behaves. o An example is a conceptual model of an atom because there is no physical model of an actual atom.  The more accurate a conceptual model, the more accurately it predicts the behavior of the system.  Economy, weather, population growth, and spread of disease and team sports are considered conceptual models. The Electron was the First Subatomic Particle Discovered  Ben Franklin learned from experiments that lightning is a flow of electrical energy through the atmosphere o Electrical energy is able to travel through different types of gasses. o (-) charged end was called the Cathode o Identical charges repel each other. o A ray behaved more like a beam of particles than a beam of light.  The greater a particles mass (inertia), the greater its resistance to a change in motion, which gives rise to a smaller deflection Electron: is the fundamental component of all atoms. All electrons are identical, each having negative electric charge. o The arrangement of electrons in atoms determine many of a materials properties, including chemical reactivity and physical attributes as taste, texture, appearance, and color. The Mass of an Atom is Concentrated in its Nucleus  It was reasoned that if atoms contained negative charged particles, some balancing positively charged matter must also exist.  The atom is mostly empty space and that most of its mass is concentrated in the atomic nucleus.  Electrons repel the electrons of neighboring atoms o Two atoms can get only so close to each other before they are repelled. o The electric force of repulsion between the atoms of the floor and those of your feet pushes you up. o Our sense of touch comes from these electrical repulsions.  Rutherford reasoned that undeflected particles traveled through regions of the gold foil that were empty space, the deflected ones were repelled by extremely dense positively charged centers. The Atomic Nucleus is Made of Protons and Neutrons Protons: The nucleus contains positively charged subatomic particles  Protons are 2000x more massive than electrons  The number of protons in a nucleus is = to the number of electrons whirling about it so the charges are balanced. Atomic Number: the number of protons in the nucleus of each atom of a given element. o Hydrogen has one proton per atom and its atomic number is 1 Neutron: adds mass to the subatomic particle. (have the same mass as protons but no electric charge) (electrically neutral) Nucleons: protons + neutrons o For any element the number of neutrons in the nucleus may vary. o Most hydrogen atoms have no neutrons. Isotopes: Atoms of the same element that contain different numbers of neutrons. Mass Number: the total number of protons plus neutrons (number of nucleons in the nucleus) o This is how we identify isotopes  The number of neutrons in an isotope can be calculated by subtracting its atomic number from its mass number 

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Mass # (protons and nutrons) - Atomic # = number of neutrons Atoms interact with one another electrically o Meaning that the way any atom ehaves in the precence of other atoms is determined largely by the charged particles it contains, especially its electrons. o Isotopes of an element differ only by mass and not by electrical charge. Atomic mass: the total mass of an atom (the sum of the masses of all the atoms components. ) Light is a Form of Energy  Surrounding every charged particle is an electric field o If an electron were to start vibrating then the electric field surrounding the electron would also start vibrating.  Electromagnetic waves are vibr...