DAT General Chemistry Exam |170|questions with complete solution

DAT General Chemistry Exam |170|questions with complete solution Atomic Number ANS-number of protons found in that atom; low number; (Z) Mass Number ANS-Protons + Neutrons; high number; (A) Atomic Mass ANS-relative mass of that atom compared to the mass of a carbon-12 atom (which is set at 12.00); measured in amu; 1 amu = ANS-1.66x10^-24 Atomic Weight ANS-weight (g) of one mole (mol) of a given element (g/mol); the weighted average of all the masses (not the weights) of an element, weighted according to the natural abundance of the isotopic species of an element 1mol = ______ (Avagadro's Number) ANS-6.022x10^23 molecules Isotope ANS-multiple species of an atom with same number of protons and a different number of neutrons (different mass numbers); generally exhibit same chemical properties Ernest Rutherford ANS-1911; gave experimental evidence that an atom has a dense, positively charged nucleus that accounts for a small portion of the volume of the atom Max Planck ANS-developed first quantum theory; 1900; proposed that energy emitted as electromagnetic radiation from matter comes in discrete bundles called quanta; E=hv (h-Planck's constant) Planck's constant ANS-6.626x10^-34 J*s The Bohr Model of the Atom ANS-developed 1913 model of H atom using Rutherford and Planck's findings; H atom has central proton, electron travels around it in a circular orbit; centripetal force acting on the electron as it revolved around the nucleus was the electrical force between the positively charged proton and negatively charged electron; quantized angular momentum so it changed in discrete amounts in relation to the quantum number (L=nh/2pi) n=quantum number h=Planck's constant; from this Energy of an electron: E=-Rh/n^2, Rh=Rydberg constant 2.18*10^-18 J/electron