MSU CEM 141 FINAL EXAM QUESTIONS AND ANSWERS VERIFIED 100% CORRECT

MSU CEM 141 FINAL EXAM QUESTIONS AND ANSWERS VERIFIED 100% CORRECT What does quantum number "n" mean? - ANSWER -Determines the energy of the electron and identifies its shell. change in matter is accompanied by a change in_______ - ANSWER -energy What does quantum number "l" mean? - ANSWER -Identifies the type of orbital (s,p,d) and subshell = 0 - n-1. change in energy caused by a change in ______ - ANSWER -forces What does quantum number "ml" mean? - ANSWER -Specifies a particular orbital within a subshell = -l - +l (2l + 1 possible values) tells us how many s,p,d orbitals are found in each sub shell. energy units - ANSWER -joule (kg/m^2s^2) and calories. What does quantum number "ms" mean? - ANSWER -Describes the spin of the electron in each orbital = +1/2 or -1/2 (only 2 e- in each orbital, each one has either + spin or - spin). kinetic energy - ANSWER -Energy in motion KE=1/2(mv^2) Aufbau Principle - ANSWER -Principle that electrons occupy the lowest level orbitals first. potential energy - ANSWER --energy associated with the position of a system of objects in a field -"stored energy" Hund's Rule - ANSWER -Rule that electrons occupy orbitals of the same energy singly until they have to pair up. total energy - ANSWER -potential+kinetic Core Electrons - ANSWER -Low in energy electrons that are close to the nucleus within the closed shell, doesn't participate in reactions. energy - ANSWER -can be transferred or transformed Valence Electrons - ANSWER -High in energy electrons that are outside of closed shell and determine reactivity. London dispersion forces - ANSWER --caused by fluctuations of electron density in molecule -causes atoms to stick together and attract -present in all neutral atoms Atomic Radius - ANSWER -Half the distance between two nuclei, increases down a group, decreases across a row Depends on attraction of protons and electrons and repulsions of electrons Represents state where forces between attraction and repulsion in an atom are equal. to lose energy ... - ANSWER -add atoms because the energy will transfer Effective Nuclear Charge - ANSWER -= Protons - Core Electrons Increases across the row, decreases down the group (as atomic radius decreases) How tight the electrons are being attracted to the nucleus. why do atoms fly apart - ANSWER -when there are collisions. and there is more kinetic energy as the temperature increases Ions - ANSWER -Atoms in which electrons have been added/removed. when a single chemical bond is broken energy is _____ - ANSWER -absorbed Cations - ANSWER -Result of removing an electron, positively charged, smaller atomic radius. Why are some London dispersion forces larger - ANSWER -because some atoms have more electrons so the electron cloud is easier to distort. Anion - ANSWER -Result of adding an electron, negatively charged, larger atomic radius. as the London dispersion forces increase the melting/boiling point ______ - ANSWER -increases because there is a stronger reaction Isoelectronic Series - ANSWER -Atoms with the same number of electrons but different number of protons, the attraction between electrons and protons increases as the charge of the nucleus increases. Why do atoms attract each other? - ANSWER -because of the attractive electromagnetic forces between them Ionization Energy - ANSWER -The energy required to remove an electron from an atom in the gas phase Decreases down a group (removing an electron gets easier as atom gets bigger), increases across a row Easier to remove a lone e- from a p orbital and the first paired e-. attractions _____ the potential energy. repulsions _____ the potential energy - ANSWER -lower; raise