2nd Term Periodical Exam Reviewer PDF

I.​ MATTER Solid -​ The arrangement of atoms is compact -​ Particles are NOT free to move Liquid -​ The arrangement of atoms is near each other, but not compact -​ Particles in a liquid can slide past each other -​ Allowing the liquid to take the shape of the container Gas...

I.​ MATTER Solid -​ The arrangement of atoms is compact -​ Particles are NOT free to move Liquid -​ The arrangement of atoms is near each other, but not compact -​ Particles in a liquid can slide past each other -​ Allowing the liquid to take the shape of the container Gas -​ Have enough energy to move freely -​ Forces between atoms are not strong enough to hold them together Plasma -​ Gas but can conduct electricity Physical Properties Flexibility - Being able to bend without breaking Density - Relationship of mass to volume Electrical conductivity - How well a material conducts electricity Hardness - Resistance to pressure, not easily scratched Thermal Conductivity - Being able to transfer heat Miscibility - Being able to form a homogenous solution Ductility - Being able to be stretched into a wire without breaking Malleability - Being able to be hammered, rolled, or pressed into thin sheets without breaking Elasticity - Being able to resume its normal shape after being stretched or tampered with Luster - Being able to shine by reflecting light Viscosity - Being able to resist flowing Melting Point - Temperature wherein solid turns to liquid Boiling Point - Temperature wherein liquid turns to gas Magnetic ability - How well an object is magnetized Brittleness - Fractures when subjected to stress, how hard something can be without cracking Solubility - Being able to be dissolved in a solvent at a specified temperature and pressure Chemical Properties Flammability - Being able to burn or ignite, causing fire Corrosivity - Being able to gradually deteriorate materials Acidity - Ability to donate a proton or accept electrons Basicity - Ability to accept protons or release electrons Physical Change -​ Limited to changes in physical properties, not composition of matter -​ Retains its state Chemical Change -​ Cannot return to the original state -​ Change in composition of matter -​ Formation of new substance -​ Changes in temperature, color, odor, formation of gas, formation of a precipitate Intensive Properties -​ These do not depend on the amount of matter Extensive Properties -​ Properties that depend on the amount of matter Law of Conservation of Matter -​ Matter is neither created nor destroyed Definition of Terms Title Definitions Pure Substance Cannot be separated by physical means or separation techniques Element Composed of only one kind of atom Compound Composed of 2 or more elements Mixture Combination of 2 or more substances, retaining their chemical properties. -​ May be separated Homogenous 1 Face, cannot determine the components in -​ Example: Saltwater, coffee Heterogenous Can determine the components -​ Example: Oil and water, Soil water Solvent Substance that dissolves -​ Water Solute Substance that gets dissolved -​ Salt Suspensions Large particle size, settle out at the bottom (For heterogenous) Colloids Have smaller particles, exhibit Tyndall effect (dispersion of light) Separation Techniques Techniques Definitions Chromatography Separates mixtures based on how substances move at different speeds through a material Decantation Pouring liquid off the top while leaving solid sediment or a denser liquid behind. Filtration Using a filter to separate solids from liquids or gases (like straining pasta). Evaporation Heating a liquid to make it turn into gas, leaving any dissolved solids behind. Distillation Heating a liquid to make it a gas, then cooling it back to liquid to separate substances based on boiling points.  II.​ ATOMIC STRUCTURE Atomic Models with Scientists: Democritus - Atomos (Indivisible) -​ Trend: Ideas -​ Coined atom; came from greek word atomos (indivisible) John Dalton - Billiard Balls -​ Trend: Scientific Method -​ Said that atom is similar to billiard balls -​ Father of Modern Atomic Theory Joseph John Thomson - Plum Pudding Model -​ Trend: Electricity -​ Said that there are negatively charged particles in an atom (electrons) -​ Cathode Ray Tubes -​ These negatively charged particles are embedded in a positive atom -​ Negative electrons, but positive atom Ernest Rutherford - Nuclear Model -​ Trend: Radioactivity -​ Discovered the positive nucleus in the center -​ Gold Foil Experiment -​ Father of Nuclear Physics Gold Foil Experiment -​ Most alpha particles pass through -​ Some deflected (positive hits positive) -​ Little returned to their original position  Electron - Negative Neutron - Neutral Proton - Positive Negatively charged Particle with no charged; Positively charged particle subatomic particle neutral -​ Apart of the nucleus -​ Outside the nucleus (the nucleus is +) III.​ ATOMIC INVENTORY A​ ​ Q ​ ​ ​ ​ X Z -​ A: Mass number/Atomic mass (Protons + Neutrons) -​ Z: Atomic Number (Number of Protons) -​ X: Element Symbol -​ Q: Charge (if applicable) Examples: 16 ​ O 8 Atomic Mass: 16 Atomic Number: 8 Number of Protons: 8 Number of electrons: 8 Number of neutrons: 8 Note: -​ Number of neutrons ( A - Z) -​ Atomic Number = Protons  -​ If normal/atom, protons = electrons Example 2: 12​ +4 ​ C 6 Mass number: 12 Atomic Number: 6 Protons: 6 Electrons: 2 This is an Ion. IMPORTANT: -​ If positive charge, subtract electrons by the number of charges -​ If negative charge, add electrons by the number of charges Atom Ion Isotope An equal number of protons Atom that either gains or If given mass number is and electrons loses electrons different from mass number -​ With charge (+ or -) of periodic table Positive: Cation Negative: Anion -​ Same number of protons, different Tip: A cat has PAW, number of neutrons PAWSITIVE IV.​ ELECTRONIC STRUCTURES OF AN ATOM Light -​ Type of wave that carries energy -​ Electromagnetic radiation of any wavelength Waves -​ Rhythmic disturbances that carry energy even without carrying a pattern Wavelength (Upside down y) - LENGTH -​ Length between 2 troughs or 2 crests Frequency (f) - FAST -​ How fast the wave moves up and down Amplitude (A) - HEIGHT -​ Height of the wave -​ ½ of the distance between the crest and trough of a wave -​ Related to brightness of light NOTE -​ Frequency and Energy has a DIRECT relationship E.g: If the frequency increases, energy also increases -​ Wavelength has an INVERSE relationship with frequency and energy E.g: If wavelength increases, both frequency and energy decrease Mechanical Waves -​ Require matter to transfer energy Electromagnetic Waves -​ NOT require matter to transfer energy  -​ Can travel in a vacuum (Empty space, no air) Types of Wave Motion: Compressional (longitudinal) -​ Waves that move parallel to the direction of the waves Compressions -​ Close to each other Rarefractions -​ Far from each other Transverse -​ Waves that move perpendicular to the direction of the wave -​ Crests and troughs are always equal in distance Black Body Radiation -​ When objects are heated, they emit radiation -​ The wavelength distribution of the radiation depends on the temperature -​ A red-hot object is cooler than a yellowish object (ROYGBIV) Max Planck - Quantum (Fixed amt. of energy that a substance can absorb) -​ In 1900, a German Physicist Max Planck solved the problem by making an assumption -​ He proposed that energy may be either released or absorbed by atoms in discrete chunks of the same minimum size Photo Electric Effect -​ The photoelectric effect happens when light hits a material and makes electrons jump out. Light is made of tiny energy packets called photons, and if a photon has enough energy, it can knock an electron free. This showed that light acts like tiny particles. Emission Spectra -​ Emission spectra are the colors of light an object gives off when it releases energy. Each element produces its own unique set of colors, like a fingerprint, because of how its electrons release energy. Scientists use this to figure out what things are made of. Line Spectra -​ Line spectra are special patterns of light made up of colored lines. Each element gives off its own set of lines when it releases energy, and these lines help scientists tell what the element is. Quantum Mechanical Model/ Electron Cloud Model -​ Trace it leaves: Electron Cloud -​ The Quantum Mechanical Model says that electrons don’t move in fixed paths like planets. Instead, they move in areas called orbitals, where there’s a high chance of finding them, like a "cloud" around the nucleus. Scientists that contributed to QMM ​ ​ De Broglie - Waves and Particles -​ Particles can behave as waves -​ Waves can behave as particles -​ Wave-particle duality of matter Schrodinger - Math function -​ His equation is a probability function -​ This probability function describes a cloud-like region where an electron is likely to be found Heisenberg - Fast objects -​ A particle's position and velocity cannot be measured simultaneously if it is moving fast. Orbitals -​ A 3D region in space where the electron is most probably found ​ Orbital Type # of orbital orientation Maximum no. of electrons S 1 2 P 3 6 D 5 10 F 7 14 Aufbau Principle:​ ​ -​ Orbitals are filled from lower to higher energy levels (ground state) -​ Arrangement of elections around the nucleus of an atom based on the energy level of each orbital Pauli Exclusion Principle  -​ No two electrons can be in the exact same place doing the exact same thing at the same time. Characteristics of Orbitals Energy Level -​ Represents the size of an orbital -​ + integers, only until 7 -​ The set of orbits with the same EL is called an electron shell Shape -​ Can have integral values of 0 to n-1 for each value of n -​ The value of L for a particular orbital is designated by a certain letter Orientation in Space -​ Defines the number of orbitals in a subshell Electron Spin -​ Up = clockwise -​ Down = counter clockwise ELECTRON CONFIGURATION -​ Distribution of electrons in the various orbitals Example: MG 12 = 12 Electrons 1s^2 - 2s^2 - 2p^6 - 3s^2 Notes:  -​ Exponents should add up to the number of electrons -​ The exponents represent the electrons Electromagnetic Spectrum RADIO - MICRO - IR - VIS - UV - XRAYS - GAMMA -​ Decreasing wavelength -​ Increasing frequency -​ Increasing energy Radio: Long-distance communication Micro: Heating appliances, radar communications Infrared: Imaging, night vision Visible Light: Spectrum that we use to see Ultraviolet: Disinfection, water purification X-rays: Imaging and medical technology Gamma rays: Radiotherapy, imaging, industrial disinfection Orbital Diagrams -​ One box per orientation -​ Up or down per electrons Hunds Rule of Maximum Multiplicity: -​ There needs to be an UP first before a DOWN -​ Hund's Rule of Maximum Multiplicity states that in orbitals of the same energy (degenerate orbitals), electrons are filled singly with the same spin (up) before pairing with electrons of opposite spin (down). This minimizes electron repulsion and creates the most stable configuration. SOURCES: -​ Chemistry Work Text Portfolio -​ Notes and slides -​ https://www.youtube.com/watch?v=bjOGNVH3D4Y AUTHORED BY:​ ​ Dmitrii Jean Maximus R. Ventura P.s: Goodluck guys! Love ya’ll!