Cheat Sheet for Intro/Phy
Chapter 19 V Chemical Bonding I. Why do atoms form bonds? 1. Most stable atoms have a filled valence shell. Most of the time this is 8 electrons. 2. Lewis Symbols V electron dot notation showing valence electrons. 3. Atoms form bonds by sharing, gaining, or losing electrons to obtain a filled valence shell. 4. The three major types of chemical bonds are Ionic bonds, Convalent bonds, and Metallic bonds. The type of bond formed depends on the Ionization Energy and electronegativity of the atoms involved. 5. Ionization energy (IE) The energy required to remove a valence electron. Metals have low IE and nonmetals have high IE. 6. Electro-negativity(EN) Very similar to electron affinity. Tendency of an atom to gain electrons, measure of how likely a given atom will steal electrons from another atom. Metals have low EN and nonmetals have high EN. Same reason as electron affinities. II. Ionic bonds. 1. When an atom with low IE is placed next to an atom with a high EN, the second atom may "steal" an electron from the first element. 2. This transfer of electrons causes the atom that lost "e" to form a smaller cation ( + charged ion) and the atom that gained "e" forms a bigger anion ( - charged ion) 3. An ionic bond is the attraction forme
Chapter 20 V Chemical Equations Reactants V On the left, what combined to give you a product. Yield sign V center part, like =. Products V End result, new substances formed in a product on the right. NaOH+HCl„³NaCl. Evidence of a chemical reaction: color change, formation of a gas, energy released/absorbed, formation of a precipitate solid. In a Chemical Reaction V What takes place? 1. Bonds between atoms can break(bonds break). 2. New bonds form. 3. Energy change has to take place. Activation Energy V To get a chemical reaction started, you need a supply of act. energy. Exothermic reaction: Reactants „³ Products + Energy. Hot, releases energy, heat enters. Endothermic V Cold, heat ends, Reactants + energy „³ products. Balancing Chemical Equations: Mono-1, di-2, tri-3, tetra-4, penta-5, hexa-6, hepta-7, octa-8, nana-9, deca-10. Types of Reactions: 1. Synthesis A+B„³AB Two simple substances combine to form a third. 2. Decomposition: AB „³A+B Single reactant breaks into two or more simple substances. 3. Combustion: CxHy+O2„³CO2+H2O Chemical reaction with oxygen that gives off heat and/or light. H2O and CO2 always produced. O2 always reactant. Energy is given off. 4. Single reaction: A+BC„³AC+b, AC+B„³ A+BC Atoms of one element replace atoms of another element in a compound. Hint: 1. Metals replace nonmetals. 2. Nonmetals replace nonmetals. 3. Metal replaces (H). 5. Double replacement: AB+CD„³AD+CB. Two compounds react to form two new compounds. Look for a precipitant. 6. Neutralization: H(x)+(y)OH„³(x)(y)+H2O Acid+Base„³Salt+Water. Solutions of an Acid. (Substance that gives up h) combines with a base (substance that has hydroxide) and produces a salt+water(NaCl+H2O). 1. History of Radioactivity A. Discovery of Radioactivity 1. March 1, 1896 by French chemist and assistants: Antoine Bequerel and assistants Marie and Piere Curie. 2. Had a piece of film next to a sample of Uranium Ore. Found a picture of a key on the film. B. Radioactivity: The release of particles and energy from the nucleus of an atom. d between + charged
Some common words found in the essay are:
IV Metallic, Review Nucleus, II Ionic, Ionic Compounds, Ionization Energy, Share Nonmetals, Cations Anions, Lewis Symbols, Crystal Lattice, A+BC Atoms, chemical reaction, bonds 1, ionic compounds, metals low, convalent bonds, filled valence, dot notation, ionization energy, low ie, bonded molecules, neutrons compared protons, convalently bonded molecules, filled valence shell, ionic compounds 1, 1 convalently bonded,
Approximate Word count = 1372
Approximate Pages = 5 (250 words per page double spaced)
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