Physics Homework 9

omework 9 Homework 9 Problem 29.8 is an energy-level diagram for a simple atom. Part A What wavelengths appear in the atom's emission spectrum? Enter your answers in ascending order separated by commas. ANSWER: λ= nm Part B What wavelengths appear in the atom's absorption spectrum? Enter your answers in ascending order separated by commas. ANSWER: λ= nm Problem 29.11 Page 1 of 6 omework 9 The allowed energies of a simple atom are 0.0 collisionally excites the atom. , 5.5 eV and eV9.0 . An eVelectron traveling at a speed of 1.9×106 m/s Part A What is the minimum speed the electron could have after the collision? Express your answer with the appropriate units. ANSWER: v= Part B What is the maximum speed the electron could have after the collision? Express your answer with the appropriate units. ANSWER: v= Problem 29.16 Part A What quantum number of the hydrogen atom comes closest to giving a 580- nm electron orbit? -diameter Express your answer as an integer. ANSWER: n= Part B isThis question will after you What the electrons speedbeinshown this state? Problem 29.44 Page 2 of 6 omework 9 A 3.13 eV photon is emitted from a hydrogen atom. Part A What is the Balmer formula nvalue corresponding to this emission? ANSWER: n= Part B What is the Balmer formula mvalue corresponding to this emission? ANSWER: m= Problem 29.60 Part A What is the energy of a hydrogen atom with a 1.69 diameter? nm ANSWER: E = eV Problem 29.61 A hydrogen atom in the ground state absorbs a 12.75 quantum jump to the next-lowest energy level. photon. eV Immediately after the absorption, the atom undergoes a Part A What is the wavelength of the photon emitted in this quantum jump? Express your answer with the appropriate units. ANSWER: Page 3 of 6 omework 9 λ= Problem 30.30 The barium isotope 133 Bahas a half-life of 10.5 years. A sample begins with 1.0×1010 133 atoms. Ba Part A How many are 133 Baatoms left in the sample after 7 years. Express your answer using two significant figures. ANSWER: N= Part B How many are 133 Baatoms left in the sample after 20 years. Express your answer using two significant figures. ANSWER: N= Part C How many are 133 Baatoms left in the sample after 190 years. Express your answer using two significant figures. ANSWER: N= Problem 30.32 Part A How many half-lives must elapse until 80 of %a radioactive sample of atoms has decayed? Page 4 of 6 omework 9 Express your answer using two significant figures. ANSWER: t t1/2 = Part B of %a radioactive sample of atoms has decayed? How many half-lives must elapse until 99 Express your answer using two significant figures. ANSWER: t t1/2 = Problem 30.39 An investigator collects a sample of a radioactive isotope with an activity of 490,000 is 150,000 Bq. . 48Bq hours later, the activity Part A What is the half-life of the sample? Express your answer using two significant figures. ANSWER: t 1/2 = h Problem 30.65 All the very heavy atoms found in the earth were created long ago by nuclear fusion reactions in a supernova, an exploding star. The debris spewed out by the supernova later coalesced to form the sun and the planets of our solar system. Nuclear 235 238 U( t 1/2 = 7.04 108yr) U( t 1/2 = 4.47 109yr) physics suggests that the uranium isotopes and should have been created in roughly equal amounts. Part A Today, 99.28 %of uranium is 238 and 0.72 U is % 235 .U How long ago did the supernova occur? ANSWER: Page 5 of 6 omework 9 t= Score Summary: yr Your score on this assignment is 0.0%. You received 0 out of a possible total of 50 points. Page 6 of 6