~Grade Ten Science Review~Chemistry Periodic Table • Metals = Left side. give up 1, 2 or 3 valence elections. Trend in a row/period = Easier to give up 1 valence electron than 2, easier to give up 2 than 3. Metals farther LEFT on the periodic table are more reactive. Trend in a column/group = Going down a column, the atomic number increases, so the valence electrons are not held as strongly. Reactivity of metals increases as you go DOWN the periodic table. Most reactive metal = Fr (Francium) Solids at room temperature, except for mercury (liquid). Are shiny (luster). Malleable (bendable). Ductile (pull into wires). Conduct electricity. Non-metals = Right side gain 1, 2 or 3 electrons to complete their outer shell. Trends in a row/period = easier to gain 1 electron than it is 2 or 3. Non-metals are more reactive on the RIGHT side of the periodic table. Trends in a column/group = Smaller atoms gain electrons easier because they are being added to a shell closer to the positive nucleus. Non-metals are more reactive at the TOP of the column. Most reactive non-metal = F (Fluorine) Some gases at room temperature, some solids, one liquid (bromine). Dull. Poor conductors. Brittle. Not ductile. Metalloids = In between metals and non-metals Solids at room temperature. Can be lustrous or dull. Maybe conduct electricity, but poor conductors of heat. Brittle. Not ductile. Sizes of Atoms Increases = Down-Left Decrease = Up-Right • • • • • • • Groups Alkali Metals = All are white/silver except for Cesium (pale gold). 1 valence electron. Soft. Highly reactive. Low-melting point. High conductivity (water). Soluble in water. All metals except for Hydrogen (H). Alkaline Earth Metals = Soluble in water. Good conductors. Silver luster. 2 valence electrons. Soft. Halogens = Non-metals. Highly reactive. 7 valence electrons. Soluble in water (form salts). Dull. Have an odour. Noble Gases = 8 valence electrons = full shell. Do not need to gain or give electrons. Gases. Colourless. Odourless. Tasteless. Low reactivity. Electrons are particles that have a negative charge and are outside the nucleus. An atom (neutral) has the same number of electrons as it does protons. Able to leave the atom to bond with a non-metal. Protons are particles that have a positive charge and are inside the nucleus. Protons can not be gained or lost. Neutrons are particles that have a neutral charge (neither positive nor negative) and are inside the nucleus. Bohr-Rutherford and Lewis (Dot Diagrams) Structures Bohr-Rutherford Structures show the full atom with the electrons orbiting the nucleus on a specific number of shells. Inside it (can) shows the number of protons and neutrons. Lewis Dot Diagrams show only the valence electrons of the atom. Potassium (K) Potassium (K) Ionic and Molecular Compounds • An ionic compound is a substance made with both cations and anions. Ionic substances tend to be electrolytes (dissolves in water to produce a substance that conducts electricity). Anions are formed when an atom gains electrons and takes on an overall negative charge. Cations are formed when an atom loses electrons and takes on an overall positive charge. An ionic bond is the attraction between the positively charged and negatively charged ions. Ions are strongly bonded to one another. High boiling point. • Distinctive edges. Usually no odour. Soluble in water. Conductible in solution Conducts when melted. Hard. Binary ionic compounds include one metallic and one non-metallic element. A molecular compound is a substance composed of molecules. Molecular substance tend to be non-electrolytes (can not dissolve in water to produce a substance that conducts electricity). A covalent bond is when atoms share electrons. Each molecule is weakly attracted to each other. Low melting point. Softer edges has an odour Sometimes soluble in water. No conductivity in solution. No conductivity when melted. Soft A molecule is a neutral particle that is composed of atoms joining together by covalent bonds. A diatomic molecule is a molecule with two of the same atoms, like fluorine (F2). Chemical Nomenclature and Formulas • • Chemical Nomenclature = Naming chemicals. Binary ionic compounds are with one metallic and one non-metallic element. Metals' names stay the same (Lithium, Aluminum), as well as most of the transition metals. Metallic ions with two different kinds of charge can be written two different ways Stock System (Standard) shows the metal name with a Roman numeral (the charge) in brackets. (Nickel (Ni) ions are “nickel (II)” or “nickel (III)”) Classical System is based on the Latin names of the elements. It changes the “um” to “ous” for the lower charge or it changes to “ic” for the ion with the higher charge. • Ferrum (iron) = ferrous or ferric • Cuprum (copper) = cuprous or cupric • Plumbum (lead) = plumbous or plumbic Non-metals have their name changed to have “ide” at the end (FluorIDE, ChlorIDE) Polyatomic Ionic Compounds are when either the cation or the anion has more than one kind of atom. Polyatomic ions: Cation = ammonium (NH3) Anions = hydroxide (OH−), carbonate (CO3 ), nitrate (NO3 ), sulfate (SO4 ), • phosphate (PO4 ), hydrogen carbonate (HCO3 ), hydrogen sulfate (HSO4 ) Binary Molecular Compounds consist of covalent bonds between two different non-metals. Add prefixes to the first non-metal and the second non-metal. Never add 'mono-' to the 3− − − 2− − 2− • first non-metal. Prefix monoditritetrapentahexa- Number 1 2 3 4 5 6 Law of Conservation of Mass Lavoisier's Law of Conservation of Mass During a chemical reaction, the total mass of the reacting substances, the reactants, is always equal to the mass of the resulting substances, the products. ex. 2H2 + O → 2H2O Dalton's Atomic Theory • • • • All matter is made up of small particles called atoms. Atoms cannot be created, destroyed, or divided into smaller particles. All atoms of the same element are identical in mass and size, but they are different in mass and size from the atoms of the other elements. Compounds are formed when atoms of different elements combine in fixed (definite) proportions. Balancing Equations in a Compound • • • Word equation: hydrogen + oxygen → water Skeleton equation: H2 + O2 → H2O Balancing = add so-efficients to both sides until the numbers on both sides are equal. 2H2 + O2 → 2H2O Type of Reactions • • Exothermic Reactions releases heat, feels warm. Eheat (heat energy) is a product. Endothermic Reactions absorbs thermal energy, feels cold Eheat is a reactant. • • • • • • Addition (Synthesis) Reactions The formation of a new compound from two or more elements or compounds. A + B → AB (only one term on right side) Decomposition Reactions The destruction of a compound into 2 or more elements. AB → A + B Single Displacement Reactions one element in a compound is replaced by another. You can tell an element's ability to replace another element in a compound from it's position on the ACTIVITY SERIES: • An element higher in the series will only displace elements lower. Lithium Potassium Barium Calcium Sodium Magnesium Aluminum Zinc Iron Nickel Tin Lead Hydrogen Copper Mercury Silver Gold Double Displacement Reactions two compounds in which the ions switch partners. Usually happens in aqueous solutions. One of the new substances (products) will be insoluble and will precipitate out of the solution AB + CD → CB + AD Combustion Reactions a hydrocarbon fuel burns in the presence of excess oxygen. Products are carbon dioxide and water. If there is not enough oxygen, then it is incomplete and additional products are carbon monoxide (poison) and carbon (ashes) Neutralization Reactions a special double displacement reaction involving an acid and a base. Products are water and salt. Neutralization • When a strong acid and a strong base are combined to create water and salt: • acid + base → water + salt example = HCl(aq) + NaOH(aq) → NaCl(aq) + H2O Acids and Bases • • • • An acid is a substance that produces hydrogen ions in a solution (H+)(aq) A base is a substance that produces hydroxide ions in a solution (OH −)(aq) Acids and bases are mostly clear and colourless. An indicator is a chemical that changes colour as the concentration of (H+)(aq) or (OH −)(aq) changes. (ex. Phenolphthalein and litmus) Indicator Acid Solution Neutral Solution Basic Solution red red red blue blue blue Red Litmus Blue Litmus Phenolphthalein Clear, colourless Clear, colourless pink • The pH scale is a scale that shows the acidity or basicity of a solution. Scale is from 0 to 14. 1 – 6.9 = acids 7 = neutral (pure water) 7.1 – 14 = bases • Concentration = amount of pure acid that is dissolved per litre of water. • Percent ionization = number of molecules that will ionize for every 100 molecules that dissolve. • Strong acids = completely ionize in water. • Weak acids = only ionize in water. • Strong bases = ionize completely in water. • Weak bases = low percent ionization. Physics RCS and Compass Direction • • RCS Direction= Rectangular Coordinate System = angle measured counterclockwise form due east. ex. 110° RCS Compass Directing = finding the angle using a protractor. ex. [N 40° W] or [W 50° N] Vocabulary • Scalar = a physical quantity that has magnitude (size), but no direction. • • • • Vector = a physical quantity that has both magnitude (size) and direction. Distance = the total length of a journey along every twist and turn of the path. It's a scalar. Displacement = describes how much an object's position has changed. (from one point to another). It's a vector. Velocity = describes the speed and direction of motion. (describes how fast an object's position is moving). It's a vector. Change in Displacement Velocity Change in Time • Speed = Describes how fast something is moving. It's a scalar. Change in Distance Speed Change in Time • Acceleration = describes how much an object's velocity changes in a certain time. It's a vector. Change in Velocity Acceleration Change in Time Converting from m/s to km/h • • km/h → m/s = /3.6 m/s → km/h = x3.6 ~Graphs~ Ecology Hierarchy of Terms • • • • • • • • • Bioshpere Biome Ecosystem Community Population Organism Organ System Organ Tissue • Cell Abiotic/Biotic Factors • • Abiotic factors are living factors. (wind, temperature) Biotic factors are non-living factors. (sunlight, animals) Food Chains • Who eats who. (Animal eats a plant, an animal eats a smaller animal, etc.) Food Webs • Complicated web of animals and plats that feed off of each other. Each plant or animal could be eaten by more than one animal. Feeding Levels • • • • First Trophic Level = Producers Second Trophic Level = Primary consumers Third Trophic Level = Secondary consumer Fourth Trophic Level = Tertiary consumer Pyramid of Numbers • The concept that the numbers of organisms decrease as one progresses towards the top of a food chain. Populations • • • • Interspecific Competition = competition amongst individuals of the same species. Intraspecific Competition = competition amongst individuals of different species. Density Dependent Factors = variable that affect a population based on the degree of crowding within the population. Density Independent Factors = variables that affect a population that are not based on the degree of crowding within the population. Carbon Cycle • • Photosynthesis = the conversion of energy from the Sun to chemical energy (sugars) by green plants. Respiration = the sum total of the physical and chemical processes in an organism by which oxygen is conveyed to tissues and cells, and the oxidation products, carbon dioxide and water, are given off. Nitrogen Cycle • • • Nitrogen Fixation = the process by which nitrogen is taken from its natural, relatively inert molecular form (N2) in the atmosphere and converted into nitrogen compounds (such as ammonia, nitrate and nitrogen dioxide). Nitrification = From ammonium to nitrites. Denitrification = converts it back into simple Nitrogen.