Chemistry Midterm
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Created by:
AmeliaMcLaren on January 10, 2012
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This is basically everything you need to know for the midterm.
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163 terms
Terms | Definitions |
|---|---|
 intrinsic | independent of how much substance is present (density, color) |
| extrinsic | dependent of how much there is (mass, volume, length) |
| pure substance | uniform throughout, cannot be physically separated |
| mixture | not necessarily uniform throughout, can be separated by physical means |
| physical change | reversible; no new substance is formed |
| chemical change | not reversible; new substance is formed |
| Elements | ______________ are the simplest example of a pure element. |
| allotrope | a structurally different form of an element |
| Compounds | ________________ are made from two or more elements that are chemically bonded. |
| molecular compound | compound made of two or more non-metals |
| ionic compound | compound made of metals and non-metals |
| homogeneous | also called a solution, uniform throughout, sodium chloride in water |
| heterogeneous mixture | not uniform throughout, like dirt in water |
| diatomic molecule | when found in nature, consists of two atoms of the same element in a covalent bond |
| Br- bromine I- iodine N- nitrogen Cl- chlorine H-hydrogen O- oxygen F- fluorine | Name the 7 diatomic molecules. |
| filtration | uses filter paper pass small particles through a sieve, based on difference in particle size (ex. dirt in water) |
| evaporation | based on difference of boiling points, water evaporates but the particles remain behind (ex. salt in water) |
| centrifugation | possible because of centrifugal force, uses a centrifuge, sort of like a merry-go-round, based on density (ex. blood) |
| decantation | uses a decanter, based on density and particle size, literally pour off less dense portion of a mixture (ex. egg yolks and whites) |
| chromatography | separating mixtures based on colors, paper ______________ works based on differences in affinity, mobile vs. stationery phase, part of the mixture likes to move and part of the mixture likes to stay behind |
| distillation | based upon difference in boiling point. this, unlike evaporation, allows you to collect both portions of the mixture |
| never significant | leading zeros are... |
| always significant | captive zeros are... |
| only significant when there is a decimal in the number | trailing zeros are... |
| always significant | counting numbers are... |
| (F-32°F) x 5°C/9°F | Formula for Fahrenheit to Celsius. |
| (C x 9°F/5°C) | Formula for Celsius to Fahrenheit |
| °C+273 | Formula for Celsius to Kelvin. |
| °K-273 | Formula for Kelvin to Celsius. |
| kg | What unit should you use to measure mass? |
| m | What unit should you use to measure length? |
| s | What unit should you use to measure time? |
| K | What unit should you use to measure temperature? |
| mol | What unit should you use to measure amount of a substance? |
| 10⁻⁹ | Giga (G) |
| 10⁻⁶ | Mega (M) |
| 10⁻³ | Kilio (k) |
| 10⁻² | Hecto (h) |
| 10⁻¹ | Deka (da) |
| 10¹ | Deci (d) |
| 10² | Centi (c) |
| 10³ | Milli (m) |
| 10⁶ | Micro |
| 10⁹ | Nano (n) |
| 2 | What is the maximum amount of electrons in the following energy level? S |
| 6 | What is the maximum amount of electrons in the following energy level? P |
| 10 | What is the maximum amount of electrons in the following energy level? D |
| 14 | What is the maximum amount of electrons in the following energy level? F |
| valence electrons | Numbers above the periodic table indicate the number of _____________ ______________ found in that group. |
| all matter is made of atoms; all atoms of a given element are identical and are different from atoms of other elements, atoms cannot be created, destroyed, or divided into smaller particles; atoms combine in simple whole number ratios to make compounds; in a chemical reaction, atoms are separated, combined, or rearranged; in nuclear reactions you convert matter to energy and vise versa | What six things did Dalton's atomic theory state? |
| matter can be destroyed through nuclear means | In Dalton's atomic theory it is stated that atoms cannot be created, destroyed, or divided into smaller particles. Why is part of this not true? |
| Isotopes are atoms of the same element that differ in their number of neutrons | In Dalton's atomic theory it is stated that all atoms of a given element are identical and are different from atoms of other elements. Why isn't this completely true? |
| proton | subatomic particle found in the nucleus with a positive charge |
| electron | negatively charged particle found outside the nucleus of the atom |
| neutron | subatomic particle found in the nucleus of the atom; it has no charge and has the same mass as a proton |
| atomic number | number of protons or number of electrons |
| as a subscript to the left of the element | How is atomic number written? |
| mass number | sum of protons and neutrons |
| as a superscript to the left of the element | How is mass number written? |
| electron configuration | describes where elements live within the atom |
| energy level, atomic orbital, and number of electrons | What 3 things does electron configuration give? |
| atomic number | In electron configuration the sum of the superscripts is the _______________. |
| noble gas | In shorthand electron configuration, you let the symbol of the ______________ preceding the valence electrons represent the electron configuration to that point. |
| stable | All the elements want to be __________. |
| half-filled, empty | The best way to be stable is to have an energy level completely filled, but if you can't fill it the way the next best thing is to be ________________. If they can't be either, they like to be _____________. |
| Cr, Cu, Mo, Ag | What elements are the four exceptions to the typical electron configurations? These give one of their s level electrons to their d level. |
| one less | D sublevels are always _______________ than the period number on which they reside. |
| has its own group, very reactive non-metal, most abundant in the universe | List the characteristics of hydrogen. |
| soft, can be cut with a dull knife; very reactive; reactive because they only have one valence; especially reactive in water; make basic solutions in water; good conductors of electricity | List the characteristics of Group 1A. |
| The Alkali Metals | Group 1A is called... |
| The Alkaline Earth Metals | Group 2A is called... |
| harder than alkali metals; reactive but not as reactive as alkali; make basic solutions in water, found in compounds with structural integrity; two valence electrons | List the characteristics of Group 2A. |
| the Transition Metals | Group 3-12B is called... |
| harder than alkali and alkaline metals; not very reactive; have varying properties; most are good conductors; all solid at room temperature except for Hg; all naturally occurring except for Tc | List the characteristics of Group 3-12B. |
| lanthanides are shiny and reactive (Ce-Lu); some are useful, Nd is used in magnets; Actinides all have at least one radioactive isotope; trans-uranium elements are atomic #93 and up, they are synthetic and radioactive | List the characteristics of the Lanthanide and Actinide Series (Inner Transition Metals). |
| the "Stair Step Elements"; semi-conductors- sometimes they insulate, sometimes they conduct | List the characteristics of The Metalloids. |
| B, Si, Ge, As, Sb, Te, Po, At | What elements are in the group of Metalloids? |
| is not | Aluminum is or is not a metalloid? |
| The Halogens | Group 17A is called... |
| most reactive non metals; combine easily with metals to form salts; halogen literally means "salt former"; consists of 2 solids, one liquid, and 2 gases at room temperature; 7 valence electrons; used for indoor lights | List the characteristics of Group 17A. |
| The Noble Gases | Group 18A is called... |
| completely stable (what every element aspires to); nonmetals; virtually nonreactive; happy valence levels; 2 valence in He, the rest have 8 | List the characteristics of Group 18A. |
| atomic radius | measured from the centers of two atoms in a homo nuclear diatomic molecule (same nucleus, two atoms). measure from nucleus and divide by two. |
| decreases, increases | Atomic radius __________ going across a period and ______________ going down a group. |
| the same energy level, farther and farther away energy levels | Atomic Size: As you move across a period, more electrons are added to ____________________. As you move down a group, more electrons are added to _________________________. |
| ionization energy | energy required to remove an electron from an atom of ion (giving the electron away). measured in kJ/mol. |
| increases, decreases | Ionization energy ____________ going across a period and _______________ going down a group. |
| As you move across a period the size gets smaller, which means electrons are held more tightly by the nucleus. If you want to obtain an electron from someone on the far right side of the periodic table, it's hard because the nucleus doesn't want to give up its valence electrons (it holds on to them more tightly) and it requires more energy to obtain the electron. So when you take an electron, you must pay in energy. As you move down a group, the nucleus doesn't care about its electrons quite as much and they stay away from the nucleus, increasing the size. This costs less energy. | Why does ionization energy increase going down a period and decrease going down a group? |
| electronegativity | the ability of an atom in a molecule to attract electrons to itself |
| increases, decreases | Electronegativity ____________ going across a period and _______________ going down a group. |
| As you move across a period there are more and more electrons in the same energy level getting closer to a noble gas. As you move down a group, electrons become farther away from the nucleus. So if you're closer to a noble gas, you want electrons, if you are far away you don't want electrons. | Why does electronegativity increase going down a period and decrease going down a group? |
| electron affinity | the energy change associated with the addition of an electron to a gaseous atom, measured in kJ/mol. (taking an electron in) |
| increases, decreases | Electron affinity __________ going across a period and ______________ going down a group. |
| As you move across a period, there are more electrons in the same energy level (getting closer to a noble gas). As you move down a group, the electrons become farther away from the nucleus. | Why does electron affinity increase going down a period and decrease going down a group? |
| negative | Electron affinity is measured in ____________ numbers, so you should think of their absolute value to decide which is larger. |
| Technetium, 1937, fission | What was the first synthetic element? When was it made? What process was used to make it (one word)? |
| 93,100, 101 | Elements with atomic numbers ____-____ are synthetic along with Tc. _____ and up are also synthetic. |
| Praseodymium, Astatine, Francium | What three elements occur so infrequently that they are considered almost unnatural? |
| Fusion | What kind of reactions is the primary source of energy? |
| 4 H nuclei fuse to form 1 He nucleus | In a fusion reaction which element fuses (and how much of it) and what does it form? |
| naturally occurring elements | He nuclei fuse to form all of the ____________ _____________ _____________. |
| energy | In a fusion reaction, mass is exchanged for __________. Following the concept put forth in E=mc² |
| nuclear fusion | primary fusion reaction in stars |
| Average= (massA x abundanceA) + (massB x abundanceB) + (massC x abundanceC) and so on | Formula for isotope problems |
| atom | representative particle for an element |
| molecule | representative particle for a molecular compound |
| formula unit | representative particle for an ionic compound |
| atoms | smaller bits of a molecular compound |
| ions | smaller bits of an ionic compound |
| 6.02 x 10²³ | Avogadro's number |
| grams (g) | What is molar mass measured in? |
| liters (l) | What is molar volume measured in? |
| molar mass | How do you go from grams to mols? |
| 6.02 x 10²³ | How do you go from mols to rp? |
| subscripts | How do you go from rp to smaller bits? |
| octet rule | states that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons |
| duet rule | the only atom that follows this rule is hydrogen, it achieves stability when it has 2 valence electrons |
| atoms transfer electrons | Ionic bonds are made when... |
| lose | Metals will _________ electrons. |
| gain | Nonmetals will __________ electrons. |
| ions | Once electrons are transferred, atoms are ________. |
| lose, gain | Atoms want to ________ or _________ electrons in order to obtain stability. |
| made of metals and nonmetals or polyatomic ions, solid, ordered arrangement called "crystal lattice", brittle, high melting point, electrical conductors in aqueous and molten phases | List the properties of ionic compounds. |
| cation | positively charged ion |
| anion | negatively charged ion |
| monotomic ions | one atom |
| polyatomic ions | many atomed |
| cation, anion | A __________ and an _________ will bond in order to make an ionic compound or salt. |
| zero | A cation and an anion will bond in order to bring the charge of the compound to _________. |
| 1. write the formula 2. determine its molar mass 3. determine the portion that each element makes up by its mass and multiply by 100. | Steps to determine percent composition (3). |
| 1. determine the possible formulas 2. determine all molar masses 3. determine the percentage of the element in each | What steps do you take if you have a problem that asks you to determine the formula of the compound? (3) (see worksheets for examples) |
| mono | Prefix meaning one. |
| di | Prefix meaning two. |
| tri | Prefix meaning three. |
| tetra | Prefix meaning four. |
| penta | Prefix meaning five. |
| hexa | Prefix meaning six. |
| hepta | Prefix meaning seven. |
| octa | Prefix meaning eight. |
| nona | Prefix meaning nine. |
| deca | Prefix meaning ten. |
| atoms | Covalent compounds are named using the prefixes to indicate how many _______ of each element are shown in the formula. |
| there is a subscript | In a covalent bond, use the prefixes on the first element if... |
| the second element | In a covalent bond always use the prefixes on ______ ____________ ___________, even if there is no subscript. |
| actual/theoretical | Formula for percent yield. |
| A + X → AX | Formula for composition reaction. |
| MCO₃ → MO + CO₂ | Formula for decomposition of a metallic carbonate. (imagine there's a triangle over the arrow) |
| MClO₃ → MCl + O₂ | Formula for decomposition of a metallic chlorate. (imagine there's a triangle over the arrow) |
| MOH → MO + H₂O | Formula for decomposition of a metallic hydroxide. (imagine there's a triangle over the arrow) |
| HgO → Hg + O₂ | Formula for decomposition of mercuric oxide. (not balanced) (imagine there's a triangle over the arrow) |
| PbO₂ → PbO + O₂ | Formula for decomposition of plumbic oxide. (not balanced) (imagine there's a triangle over the arrow) |
| NaCl → Na + Cl₂ | Formula for electrolysis of sodium chloride. (not balanced) |
| H₂O → H₂ + O₂ | Formula for electrolysis of water. (not balanced) |
| HA → H₂O + A | Formula for decomposition of an acid. (imagine there's a triangle over the arrow) |
| AX + B → BX + A | Formula for a single replacement reaction. |
| AX + BY → AY + BX | Formula for a double replacement reaction. |
| CxHy + O₂ → CO₂ + H₂O | Formula for combustion of a hydrocarbon. (imagine there's a triangle over the arrow) |
| 1. write a balanced equation 2. find the molar masses 3. if ____ gs of A how many of B do you need? 4. do I have what I need? -if you do- excess -if you don't- limiting 5. go to LR to find out how much should be produced | Steps for a stoichiometry problem. (5) |
| hydrate | To name a ___________, use the name of the compound, then prefixes before hydrate. |
| molecular compound | To name a __________ __________ use prefixes like hydrates + ide. |
| drop ide + ic + hydro + acid | If an acid contains an ion or compound that ends with "IDE" then... |
| drope ite + ous + acid | If an acid contains an ion or compound that ends with "ITE" then... |
| drope ate + ic + acid | If an acid contains an ion or compound that ends with "ATE" then... |
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