Chemistry Unit #2A
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76 terms
Terms | Definitions |
|---|---|
 Democritus | ____ was the first one to use the term "atom" as a building block of matter. |
| Antoine Lavoisier | ____ studied chemical reactions and made the law of conservation of mass. |
| Law of conservation of mass | mass of reactants = mass of products, mass is neither created nor destroyed during ordinary chemical reactions or physical changes |
| guillotine | Lavoisier was killed by a ______. |
| Joseph Proust | ________ took compounds and chemically analyzed them and their composition, making the law of definite proportions. |
| law of definite proportions | a chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound |
| John Dalton | _______ studied multiple compounds that contained the same elements but different amounts of them and made the law of multiple proportions. |
| law of multiple proportions | if 2 or more different compounds are composed of the same 2 elements, then the ratio of the masses of the 2nd element combined with a certain mass of the 1st element is always a ratio of small whole numbers |
| Dalton | Who made the original atomic theory? |
| atoms (1) ; identical (2) ; differ (2); subdivided (3); created (3); destroyed (3); whole (4); compounds (4); combined (5); separated (5); rearranged (5) | Original atomic theory: 1. All matter is composed of extremely small particles, called ____. 2. Atoms of a given element are ____ in size, mass, and other properties. Atoms of different elements ___ in size, mass, and other properties. 3. Atoms cannot be ____, ____, or ____. 4. Atoms of different elements combine in simple ____-number ratios to form chemical _____. 5. In chemical reactions, atoms are ____, _____, or ____. |
| J.J. Thompson | _____ used the cathode ray tube and found he could make rays bend with a magnet, deciding rays were made of negative particles. |
| Plum Pudding | J.J. Thompson's ____ ____ idea about atom arrangment was completely wrong. |
| Robert Millikan | ______ experimented with oil drops, finding he could make adjustments to negative particles and thus suspend oil drops in air. |
| Millikan | Who collected data to give us a charge for electrons? |
| 1.60 X 10^-19 C (C means coulomb) | what is the charge for an electron? |
| Max Planck | _____ studied particle behavior in electrons, and came up with the idea of energy jumping levels. |
| Max Planck | Who made Planck's constant? |
| Niels Bohr | _____ made a model of electrons in circles orbiting around a positive nucleus. |
| Louis de Broglie | _____ studied wave patterns of emitted light. |
| Erwin Schrodinger | _____ was a theoretical chemist who wrote math calculations and equations, made Quantum Theory, and explained why electrons sometimes act as particles and sometimes as waves. |
| 7 | There are ___ main energy levels. |
| valence | Lewis Structure only shows ____ electrons. |
| orbitals | In orbital notation, the lines under the arrows represent ____. |
| electron configuration; orbital notation; lewis structure; noble gas configuration | What are the four methods of writing an element's electrons that we learned? |
| quantum theory | the study of the structure and behavior of the atom and of subatomic particles from the view that all energy comes in tiny, indivisible bundles |
| quantum | basic unit of electromagnetic energy; it characterizes the wave properties of electrons |
| photon | a unit or quantum of light; a particle of electromagnetic radiation that has zero rest mass and carries a quantum of energy |
| orbital | a region in an atom where there is a high probability of finding electrons |
| valence electron | an electron that is found in the outermost shell of an atom and that determines the atom's chemical properties |
| electron configuration | the arrangement of electrons in an atom |
| electron-dot notation | an electron-configuration notation in which only the valence electrons of an atom of the particular element are shown, indicated by dots placed around the element's symbol |
| heisenberg uncertainty principle | the principle that states that determining both the position and velocity of an electron or any other particle simultaneously is impossible |
| aufbau principle | the principle that states that the structure of each successive element is obtained by adding one proton to the nucleus of the atom and one electron to the lowest energy orbital that is available |
| hund's rule | the rule that states that for an atom in the ground state, the number of unpaired electrons is the maximum possible and these unpaired electrons have the same spin |
| Pauli exclusion principle | the principle that states that 2 particles of a certain class cannot be in exactly the same energy state |
| paramagnetic | substances that are slightly attracted to a magnetic field due to the presence of unpaired electrons |
| diamagnetic | substances not attracted to a magnetic field (maybe slightly repelled) because all electrons are paired |
| s, p, d, f | what are the four energy sublevels? |
| energy levels | The 7 periods on the periodic table represent 7 ___ ____. |
| 2; 1 | S sublevel can hold __ electron(s), __ orbital(s). |
| 6; 3 | P sublevel holds ___ electrons, requires __ orbitals. |
| 10; 5 | D sublevel holds ___ electrons, requires ___ orbitals. |
| 14; 7 | F sublevel holds __ electrons, requires __ orbitals. |
| preceding; square brackets | In Noble Gas configuration, the chemical symbol for the ___ noble gas is placed in ___ ___. |
| isotope | an atom that has the same number of protons (or same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different atomic mass). |
| atomic number | the number of protons in the nucleus of an atom; this is the same for all atoms of an element |
| mass number | the sum of the numbers of protons and neutrons that make up the nucleus of an atom |
| nucleon | a proton or neutron |
| nuclide | an atom that is identified by the number of protons and neutrons in its nucleus |
| atomic mass unit (abbreviation: amu) | a unit of mass that describes the mass of an atom or molecule; it is exactly 1/12 of the mass of a carbon atom with mass number 12 |
| average atomic mass | the weighted average of the masses of all naturally-occurring isotopes of an element |
| Ernest Rutherford | ____ identified the positive nucleus with the gold foil experiment, proving the Plum Pudding idea to be wrong |
| James Chadwick | ____ discovered neutrons using x-rays (they have no charge). |
| mass; atomic | In an element's nuclear symbol, the top left corner has the ____ number, and the bottom left corner has the ___ number. |
| Average atomic mass | _____ = (isotope #1's relative abundance) (isotope #1's actual mass) + (isotope #2's relative abundance) (isotope #2's actual mass) |
| name of element; mass number | Hyphen notation consists of the ____-____ |
| amu | what is the abbreviation for atomic mass unit? |
| atomic radius | ____ is found by smooshing two atoms of the same element together, measuring from nucleus to nucleus, and dividing by two. |
| Angstrom | What is the unit for atomic radius? |
| nanometer | What is another name for an Angstrom? |
| ionization energy | _____ is the energy needed to remove a valence electron. |
| Joules (J) or kcal/mole | What two units are used for ionization energy? |
| cation | A ____ is a positively charged atom. |
| metals | ___ form cations. |
| smaller | Cations are always ___ than the atom from which they were formed. |
| 1+ | If an atom is a cation, put a ___ in the top righthand corner of the nuclear symbol |
| electron affinity | ____ is the energy change that occurs when an electron is added to the valence shell. |
| anion | A(n) ____ is a negatively charged atom. |
| nonmetals | ____ form anions. |
| larger | Anions are always ___ than the atom from which they were formed. |
| Joules (J) or kcal/mole | What units of energy can be used for electron affinity? |
| fluorine; 4 | What element has the highest electronegativity? What is its electronegativity? |
| electronegativity | ____ is the control the nucleus has over bonding electrons in the valence shell. |
| no unit of measure | How is electronegativity measured? |
| increases; decreases; decreases; decreases | When going down a group, atomic radii ____, ionization energy ____, electron affinity ____, and electronegativity ___. |
| decreases; increases; increases; increases | When looking from left to right in a period, atomic radii ____, ionization energy ___, electron affinity ____, and electronegativity ____. |
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