Summary

This document details the different states of matter (solid, liquid, gas and plasma), including their properties and changes of state. It also discusses pure substances, mixtures, separation techniques and phase diagrams.

Full Transcript

Welcome! Learning Outcomes Three states of matter, and changes of state Atomic theory Atoms, molecules and ions The kinetic model and changes of state Separating and purifying substances Diffusion Filtration and use of a separating funnel Atom...

Welcome! Learning Outcomes Three states of matter, and changes of state Atomic theory Atoms, molecules and ions The kinetic model and changes of state Separating and purifying substances Diffusion Filtration and use of a separating funnel Atomic structure and sub-atomic particles Crystallisation and distillation Proton number and nucleon number Paper chromatography Isotopes Criteria of purity Relative atomic mass Elements and compounds Arrangement of electrons in atoms “Blue Marble” What makes the Earth unique compared to other planets? States of Matter Let's Review Matter Matter is anything that has mass and takes up space (volume), and it can exist in three different states: solid, liquid, or gas. Solid Liquid Gas Let's Review Matter Plasma fourth state of matter an electrically charged gas that are affected by electrical and magnetic fields Let's Review Matter With a partner, talk about the properties each state of matter possess. Consider the following: volume, density, shape, fluidity Solid Liquid Gas Let's Review Matter Solid Liquid Gas “Fluids” they can be made to flow or move Solids have a definite Liquids have a definite Gases have widely spaced shape, volume, high volume, an indefinite particles that move rapidly, density, are shape, a high density, and have a low density, and are incompressible, rigid, and are incompressible. highly compressible. have low diffusivity. Let's Review Matter SOLID LIQUID GAS I: expands I: expands I: expands temperature D: contracts D: contracts D: contracts increased unaffected slightly easily pressure volume compressible compressed Let's Review Matter Let's Review Matter Enter the link then click States. https://phet.colorado.edu/sims/html/states-of-matter- basics/latest/states-of-matter-basics_en.html PHET Colorado- States of Matter: Basics Kinetic Model Theory states that... all matter is made up of tiny particles all particles are in constant random motion arrangement of particles is different for each state the more often the particles collide with the wall from the container, the greater the pressure Kinetic Model Theory increasing temp melting point boiling point (m.p.) (b.p.) decreasing temp Note: A substance's m.p. and b.p. in relation to room temperature (20 °C) determine its state. If m.p. is below 20 °C and b.p. is above 20 °C, the substance will be a liquid at room temperature Evaporation takes place from the surface of the liquid the larger the surface area and warmer the liquid is, the faster the liquid evaporates Boiling takes place over the large mass of the liquid, produces lots of bubbles Volatility tendency of a substance to evaporate at normal temperatures Volatile Liquid evaporates easily and has a relatively low boiling point ethanol (78 °C) is more volatile than water (100 °C) Boiling Point changes depending on the surrounding pressure (atmospheric pressure or standard pressure) atmospheric pressure is directly proportional to the boiling point of a liquid water: 100° C at standard pressure; around 120° C in a pressure cooker; < 100 °C on high mountains Learning Outcomes Three states of matter, and changes of state Atomic theory Atoms, molecules and ions The kinetic model and changes of state Separating and purifying substances Diffusion Filtration and use of a separating funnel Atomic structure and sub-atomic particles Crystallisation and distillation Proton number and nucleon number Paper chromatography Isotopes Criteria of purity Relative atomic mass Elements and compounds Arrangement of electrons in atoms Any questions? Spread kindness. ☺ Welcome! Learning Outcomes Three states of matter, and changes of state Atomic theory Atoms, molecules and ions The kinetic model and changes of state Separating and purifying substances Diffusion Filtration and use of a separating funnel Atomic structure and sub-atomic particles Crystallisation and distillation Proton number and nucleon number Paper chromatography Isotopes Criteria of purity Relative atomic mass Elements and compounds Arrangement of electrons in atoms Pure Substance Mixture Pure Substances Pure Substances ✿ consists of only one substance; no impurities ✿ melts and boils at definite temperatures ✿ m.p. and b.p. values are precise and predictable Element composed of only one type of atom Compound formed by two or more different types of elements that are united chemically in fixed proportions SUBSTANCE STATE AT ROOM TEMP M.P. B.P. oxygen gas -219 -183 nitrogen gas -210 -196 ethanol (alcohol) liquid -117 78 water liquid 0 100 sulfur solid 115 444 sodium chloride (salt) solid 801 1465 copper solid 1083 2600 carbon dioxide gas -78 -56.6 (5.11 atm) Water bath apparatus for measuring m.p. of a solid (below 100° C) Oil bath apparatus for measuring m.p. of a solid (above 100° C) Impurities Effect ✿ lowers melting point ✿ raises boiling point ✿ changes may spread over a range of temperatures in each case Phase Change Diagram a graphical representation of the physical states of a substance under different conditions of temperature and pressure Heating Curve ✿ heating curve for a pure solid stops rising at its melting point ✿ heating curve for a mixture shows a range of temperature ✿ heating makes the molecules move faster ✿ heat energy is released Heating Curve pure substance mixture Cooling Curve ✿ temp stays constant while gas condenses and while liquid freezes ✿ cooling makes the molecules move slower ✿ heat energy is needed Cooling Curve Salt and Ice Salt lowers the freezing point of the water. Ice absorbs energy as it melts since the outside temperature is no longer cold enough to maintain the frozen structure. Phase Change Diagram When a solid is melted, or a liquid is boiled, the temperature stays constant until the process is complete. The same is true in reverse when a gas condenses or a liquid freezes. Mixture Mixture ✿ made from at least two parts, which may be solid, liquid or gas Homogenous Mixture have a uniform composition cannot be separated physically Heterogenous Mixture composition is not uniform can be separated physically Solution the states are completely mixed to become one single state or phase a solvent completely dissolves the solute salt solution, acetone, soft drinks, etc. Concentrated Dilute solutions in which there solutions in which there are more solute than the are more solvent than solvent, high proportion the solute, small of solute proportion of solute Think-Pair-Share How will you separate the following mixtures? 1. salt from seawater 2. water from seawater 3. sand from sand and water mixture 4. oil and water 5. alcohol and water 6. mixture of salt and iron fillings Suspension the solutes do not dissolve but remain suspended in the solvent sand and water, salad dressings, chalk in water, etc. Separa ting Techniques Separating and Purifying Substances The most useful separation method for a particular mixture depends on... ✿ type of mixture ✿ which substance you’re most interested in MIXTURE METHOD OF SEPARATION use of some difference in properties (density, solid + solid (powdered) solubility, magnetism) suspension of solid in liquid filtration or centrifugation liquid + liquid (immiscible) use a separating funnel or decantation to obtain solid: use evaporation/crystallisation solution of solid in liquid to obtain liquid: use distillation two or more liquids mixed together (miscible) fractional distillation solution of to or more solids in a liquid chromatography Decantation used to separate a suspension once the solid has settled to the bottom, the liquid can be carefully poured off. Filtration a useful method for separating solids from liquids in a suspension residue - the insoluble material collected on filter paper filtrate - the liquid phase collected Centrifugation another method of separating insoluble solid from a liquid where mixture is spun at high speed in a centrifuge which causes the solid to be deposited at the bottom of the centrifuge tube Separating Immiscible Liquids Mixtures of immiscible liquids can be separated if the mixture is placed in a separating funnel and allowed to stand. The liquids separate into different layers. The lower, denser layer is then “tapped” off at the bottom. Separating Mixtures of Solids The separation of a solid from a mixture depends largely on the particular substance being purified. Separation can be based on differences in density, magnetic properties or sublimation. Separations based on differences in Solubility Evaporation and Crystallisation - can be used to obtain a soluble solute from a solution. Crystallisation is used specifically if there are two or more soluble solute in the solution. Crystallisation 1. Prepare a saturated solution. 2. Filter the solution to remove insoluble solute. 3. Partially evaporate the solution. 4. Cool down the solution. 5. Filter the solution to remove the crystals. 6. Dry the crystals by pressing in between the filter paper. Separating Solutions Simple Distillation- used to collect or separate the liquid solvent in a solution. The liquid is more volatile than the dissolved solid and can easily be evaporated then pass in a condenser. distillate - the water collected after distillation Fractional Distillation used to separate a mixture of two or more miscible liquids with different boiling points. Chromatography It is used in separating two or more dissolved solids in solutions. The substances separate according to their solubility in the solvent. Many different solvents are used in chromatography (water and organic solvents such as alcohol) Chromatography Solvent front - the maximum distance reached by the sample. Datum line/Origin - where you add/put the sample mixture. Locating agents - added to colourless mixture to make it soluble. Retention factor or Rf - the ratio between the distance moved by a particular spot related to the position of the solvent front. Rf = distance moved by the substance / distance moved by the solvent front Paper Chromatography a test that can be used to check for the purity of the substance. If the sample is pure, it should only give one spot when run in several different solvents. The identity of the sample can also be checked by comparing its Rf value to that sample we know to be pure. Diffusion used to separate a mixture of two or more gases. The gas which has a lower mass will diffuse faster. Diffusion Diffusion in liquids is slower than gases; does not occur in solids. Molecules randomly move from an area where they are most concentrated, to areas of lesser concentration until particles are evenly spread out. (equilibrium) Any questions? Answer Questions C2.01-C2.010 pp. 192 & 197 Learning Outcomes Three states of matter, and changes of state Atomic theory Atoms, molecules and ions The kinetic model and changes of state Separating and purifying substances Diffusion Filtration and use of a separating funnel Atomic structure and sub-atomic particles Crystallisation and distillation Proton number and nucleon number Paper chromatography Isotopes Criteria of purity Relative atomic mass Elements and compounds Arrangement of electrons in atoms Spread kindness. ☺ Welcome! Learning Outcomes Three states of matter, and changes of state Atomic theory Atoms, molecules and ions The kinetic model and changes of state Separating and purifying substances Diffusion Filtration and use of a separating funnel Atomic structure and sub-atomic particles Crystallisation and distillation Proton number and nucleon number Paper chromatography Isotopes Criteria of purity Relative atomic mass Elements and compounds Arrangement of electrons in atoms Elements & Compounds Elements Compounds consists of only one made up of two or more type of atom which all elements that are have the same numbers chemically bound of protons in their nuclei together in a fixed ratio Oxygen, Hydrogen, Sodium Chloride (NaCl) Carbon Dihydrogen Oxide (H20) Carbon Dioxide (CO2) Elements mass of Universe: hydrogen (92%), helium (7%), other elements (1%) human body: 65% oxygen, 18% carbon, 10% hydrogen, 3% nitrogen, 2% calcium, 2% other elements Compounds COMPOUND MIXTURE The substances chemically react together to The substances are simply mixed together; form a new compound no reaction takes place The composition of the new compound is The composition of the mixture can be varied always the same The properties of the new compound are The properties of the substances present very different from those of the elements in it remain the same The substances in the mixture can be The compound cannot easily be separated separated by physical methods such as into it's elements filtration, distillation Chemical Reaction 1. new chemical substance(s) are formed 2. usually the process is not easily reversed 3. energy is often given out Decomposition a compound breaks down to form two or more substance Synthesis a substance formed by the combination of two or more other substances Physical Change substances involved do not change identity can be easily returned to their original form Chemical Change substances involved combine or decompose to form one or more different substances Give examples that shows: Physical Change Chemical Change In groups, make a research about the development of the Atomic Theory. Create a timeline showing the different scientists and their contribution to the Atomic Theory. Atom s & Molecules Atomic Theory a scientific concept that explains the nature of matter and its behavior. Solid Sphere Model Plum Pudding Model Nuclear Model of Atomism of the Atom of the Atom the Atom Atomic Theory Mechanical Wave Planetary Model Electron Cloud Model Model Atomic Theory 01 5th Century BC Atomism Atomism is a theory that was first proposed by the ancient Greek philosopher Democritus. According to atomism, all matter is made up of tiny, indivisible particles called atomos, which are in constant motion and are too small to be seen with the naked eye. 1804 Atomic Theory 02 Solid Sphere Model John Dalton's Solid Sphere Model of the Atom states that atoms of a given element are identical in size, mass, and other properties. Atoms of different elements differ in size, mass, and other properties. Atoms cannot be subdivided, created, or destroyed. Further experimental observations under the microscope showed the random motion of dust Solid Sphere Model particles in suspension in water or smoke particles of the Atom in air (Brownian motion) Atomic Theory 03 1898 electron Plum Pudding Model J.J. Thomson proposed that the atom is composed of a positively charged sphere with negatively charged electrons distributed throughout it. The negatively charged electrons were embedded in a positively charged "pudding" of matter, which made up most of the atom's mass. Atomic Theory 04 1909 Nuclear Model electron Ernest Rutherford proposed that most of the mass of the atom is concentrated in a tiny, positively nucleus charged nucleus at the center, with negatively charged Ernest Rutherford’s Nuclear Model of the Atom electrons orbiting around it. Atomic Theory 05 1913 Planetary Model Niels Bohr proposed that the electrons travel around the nucleus of an atom in distinct circular orbits, or shells. The electrons orbit around the nucleus similar to how planets orbit around the sun. Atomic Theory 06 1926 Electron Cloud Model Werner Heisenberg and Erwin Schrodinger proposed that there is a particular area in which an electron is likely to be and does not have a set path around it. Atomic Theory 07 1926 Wave Mechanical Model “Quantum-Wave Model" was proposed by Erwin Schrodinger based on the studies of De Broglie, Bohr and Sommerfeld. The wave mechanical model proposed that the electrons act like particles as well as waves of energy. Electrons occupy orbitals. Orbitals are nothing like orbits. They are areas of probability (90% of electron probability). John Dalton a pure element is composed of atoms the atoms of each element are different in size and mass atoms are the smallest particles that take part in a chemical reaction atoms of different elements can combine to make molecules of a compound Chemical Language suggested that each element should have its own symbol element symbols uses letters from the name or from their Latin name Element Latin name Symbol hydrogen H helium He calcium Ca copper cuprum Cu sodium natrium Na gold aurum Au Copper + Tellurium Decode This! Nickel + Cerium Cobalt + Oxygen + Potassium + Iodine + Einsteinium Iodine + Cobalt + Nickel + Carbon Carbon + Holmium + Cobalt + Lanthanum + Tellurium Kinetic Model Theory states that... all matter is made up of tiny particles all particles are in constant random motion arrangement of particles is different for each state the more often the particles collide with the wall from the container, the greater the pressure Kinetic Model Theory the higher the temperature, the higher the average energy of the particles In a gas, the faster the particles are moving, the higher the temperature Intermolecular Space Diffusion the process by which different fluids mix as a result of the random motions of their particles involves the movement of particles from higher concentration to lower concentration eventually the particles are evenly spread - their concentration is the same throughout (equilibrium) does not take place in solids diffusion in liquids is much slower than in gases. Kinetic Model Theory & Diffusion heavier particles move more slowly than lighter particles at the same temperature; larger molecules diffuse more slowly than smaller ones. pressure of a gas is the result of collisions of the fast-moving particles with the walls of the container average speed of the particles increases with an increase in temperature Any questions? Answer Questions C2.11-C2.15 page 203 Learning Outcomes Three states of matter, and changes of Atomic theory state The kinetic model and changes of Atoms, molecules and ions state Separating and purifying substances Diffusion Filtration and use of a separating funnel Atomic structure and sub-atomic Crystallisation and distillation particles Paper chromatography Proton number and nucleon number Criteria of purity Isotopes Elements and compounds Relative atomic mass Arrangement of electrons in atoms Learning Outcomes Three states of matter, and changes of state Atomic theory Atoms, molecules and ions The kinetic model and changes of state Separating and purifying substances Diffusion Filtration and use of a separating funnel Atomic structure and sub-atomic particles Crystallisation and distillation Proton number and nucleon number Paper chromatography Isotopes Criteria of purity Relative atomic mass Elements and compounds Arrangement of electrons in atoms Welcome! LearningObjectives 1. Atoms and Molecules 2. Ions, Cations, and Anions 3. Atomic structure and sub-atomic particles 4. Proton number and nucleon number Atom basic unit of matter and the smallest particle of an element that shows its properties and characteristics Molecule a group of two or more than two atoms of the same or different elements that are chemically bonded together two atoms of hydrogen and one atom of oxygen react with each other and form one molecule of water Ion an atom or group of atoms that has an electric charge which is formed by the loss or gain of electrons in an exchange reaction Cation Anion positively charged particle negatively charged particle losing electrons makes the gaining electrons makes the atom positively charged atom negatively charged more protons than electrons more electrons than protons + 2+ - Na , Ca , and Cl Atom and its Structure Nucleus positively charged at the center of an atom contains protons and neutrons electrons orbit around it Atom and its Structure The nucleus of an atom is actually In perspective, if we imagine an atom about 100,000 times smaller than were the size of a stadium, the nucleus the overall size of the atom. would be smaller than a grain of sand. Atom and its Structure Proton Neutron Electron located in the nucleus located in the nucleus orbit around the nucleus has one positive no electrical charge/ has one negative charge charge (+1) neutrally charged (-1) has a mass of 1 unit has a mass of one unit has hardly any mass p+ n e- Sub-atomic Particles Sub-atomic Relative Relative Location particle Mass Charge proton 1 +1 nucleus neutron 1 0 nucleus 1/1840 outside electron -1 (negligible) nucleus Mass Number Atomic Number nucleon number proton number has the symbol A has the symbol Z total number of protons equal to the proton and neutrons number equal to the electron number of a neutral atom Neutral Atom Ions p+ = e- = z Z = p+ A = p+ + n A = p+ + n For electrons: positive charge: subtract to p+ negative charge: add to p+ Periodic Table Proton number increases by 1 when you go to the right When you go one element down, you increase proton number by 8 in the first 3 periods (transition elements not included) Hydrogen simplest atom of all one proton and one electron no neutrons Helium second simplest atom 2 protons, 2 electrons, 2 neutrons Total mass: 4 units (p+n) Formulas for Neutral Atoms: proton/ atomic number (Z) = # of protons nucleon/ mass number (A) = protons + neutrons electrons (e-) = protons = atomic number neutrons (n) = nucleon number - proton NUCLEON ELEMENT PROTON ELECTRON NEUTRON NUMBER 39 19 K 19 19 20 39 238 92 U 7 3 Li 11 5 B 12 6C Formulas for Ions: proton/ atomic number (Z) = # of protons nucleon/ mass number (A) = protons + neutrons electrons (e-) = if (+) p - charge = if (-) p + charge neutrons (n) = nucleon number - proton NUCLEON ELEMENT PROTON ELECTRON NEUTRON CHARGE NUMBER 35 2+ 17 Cl 17 15 18 35 +2 23 1+ 11 Na 195 4+ 78 Pt 11 3+ 5 B 48 3+ 22 Ti Let’s Practice! MASS ELEMENT PROTON NEUTRON ELECTRON NUMBER 39 19 K 238 92 U 7 3 Li 11 5 B 12 6C MASS ELEMENT PROTON NEUTRON ELECTRON CHARGE NUMBER 35 2+ 17 Cl 23 1+ 11 Na 195 4+ 78 Pt 11 3+ 5 B 48 3+ 22 Ti NUCLEON ELEMENT PROTON ELECTRON NEUTRON CHARGE NUMBER Ca 20 22 -3 O 8 16 -2 Br 35 45 +5 N 7 7 -3 Al 13 10 27 Do It On Your Own NUCLEON ELEMENT PROTON ELECTRON NEUTRON CHARGE NUMBER N 7 14 -3 F 9 10 10 Ne 10 10 0 Be 4 2 9 S 16 32 0 Mg 12 12 +2 H 1 1 1 Welcome! Learning Outcomes Three states of matter, and changes of state Atomic theory Atoms, molecules and ions The kinetic model and changes of state Separating and purifying substances Diffusion Filtration and use of a separating funnel Atomic structure and sub-atomic particles Crystallisation and distillation Proton number and nucleon number Paper chromatography Isotopes Criteria of purity Relative atomic mass Elements and compounds Arrangement of electrons in atoms Mass Spectrometer an analytical tool useful for measuring the mass-to-charge ratio of one or more molecules present in a sample Relative Atomic Mass average mass of naturally occurring atoms of an element compared to a mass of carbon (exactly 12 units) Standard: Carbon-12 Symbol: Ar Element Atomic Symbol Relative Atomic Mass carbon C 12 hydrogen H 1 oxygen O 16 calcium Ca 40 copper Cu 64 gold Au 197 Isotopes atoms of an element with the same atomic number and position in the periodic table and nearly identical chemical behavior but with different atomic masses and physical properties proton = electron ≠ neutron ≠ nucleon number Radioisotopes have unstable nuclei emit various forms of radiation naturally occurring (carbon-12, carbon-13, carbon-14, uranium-238, uranium-235) or artificially produced (tritium, cobalt-60, cesium-137, iridium-192, radium-226) Isotopes Element Isotopes Carbon-12 Carbon-13 Carbon-14 6 protons 6 protons 6 protons Carbon 6 neutrons 7 neutrons 8 neutrons 6 electrons 6 electrons 6 electrons Chlorine-35 Chlorine-37 17 protons 17 protons Chlorine 18 neutrons 20 neutrons 17 electrons 17 electrons Neon-20 Neon-21 Neon-22 10 protons 10 protons 10 protons Neon 10 neutrons 11 neutrons 12 neutrons 10 electrons 10 electrons 10 electrons Electronic Structure Bohr’s Theory Electrons are in orbit around the central nucleus Electron orbits are called shells or energy levels Shells further from the nucleus have higher energies Shells are filled starting with the one with the lowest energy (closest to the nucleus) 2-8-8-18 rule Example: 2, 6 Example: 2, 8, 5 Example: 2, 8, 8, 2 Let’s Try! Illustrate the electron arrangement of each atom in rings and its numbers. 3 Li 11Na 7N 14 Si 18 Ar Ele ctron Configuration Electron Configuration the distribution of electrons of an atom or molecule in atomic or molecular orbitals Subshells s = 2 p = 6 d = 10 f = 14 Helium 2 Carbon 2, 4 Potassium 2, 8, 8, 1 Sodium Argon Magnesium Aluminium Let’s Try! Identify the electron configuration of the following: 17 Cl 8O 15P 13 Al 1 H Do It On Your Own Electron Structure Electron Configuration 2 He 17 Cl 18Ar 3 Li 8O 15P 1H 14 Si 4 Be 13Al 19K 16 S 5 B 12 Mg 9F 7 N 20 Ca 10 Ne 6 C 11 Na Learning Outcomes Three states of matter, and changes of state Atomic theory Atoms, molecules and ions The kinetic model and changes of state Separating and purifying substances Diffusion Filtration and use of a separating funnel Atomic structure and sub-atomic particles Crystallisation and distillation Proton number and nucleon number Paper chromatography Isotopes Criteria of purity Relative atomic mass Elements and compounds Arrangement of electrons in atoms Electron Configuration Exercise 17 Cl 3 Li 9F 14 Si 13Al 16 S 12 Mg 7 N 10 Ne 11 Na Exercise Sub-atomic Electron Electron Structure Particles Configuration 197 79Au 3 Li 2 He 18Ar 8O 1H 238U 92 14 Si 20Cl 16 S 4 Be 19K 40 5 B 9F 23 Na 11 7 N 20 Ca 6C 12 C Na 6 11

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