REV09 - CHM 115 Review Final Exam: May 4th 2009 Elliot Hall...

Info iconThis preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon
CHM 115 Review Final Exam: May 4th 2009 Elliot Hall of Music 1:00 pm 35 Questions, 210 points 2 Hours Be there!
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Think/Pair/Share Question #1 How many nucleons are in a 19 F nucleus? (Answer with a number.) 9 Mass number, # of protons + neutrons = # of nucleons Symbol Atomic number, number of protons 19 F 9
Background image of page 2
Types of Radioactive Decay a helium nucleus , an electron , a photon, no charge, no mass e -1 0 +2 4 He Some elements undergo spontaneous decay to form more stable elements γ α β
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
98 98 229m Th 90 229 Th 90 212 Po 84 208 Pb 82 Tc 43 Ru 44 a. b. c. Question #2 Which change involves alpha-decay ? (unstable nucleus to stable nucleus)
Background image of page 4
Which change involves alpha-decay ? Tc 43 Ru 44 a. 229m Th 90 229 Th 90 b. 212 Po 84 208 Pb 82 c. Nuclear equations 98 98 + e -1 0 + He 4 +2 + Σ reactant atomic numbers = Σ product atomic numbers Σ reactant mass numbers = Σ product mass numbers γ 0 0
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Question #3 Σ reactant atomic numbers (charge) = Σ product atomic numbers (charge) Σ reactant mass numbers = Σ product mass numbers Identify the atomic number of X. 25 12 Mg + 4 2 He A Z X + 1 1 H
Background image of page 6
Mass defect Mass of nucleus is not equal to the sum of the masses of individual nucleons in the nucleus. 14 7 N 7 1 1 H + 7 1 0 n 14.0031 amu 14.11543 amu The 14 7 N nucleus is missing 0.1123 amu. This is the mass defect.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
E = mc 2 or E = mc 2 E = energy (in J) produced when mass m is converted into energy or consumed when energy is converted to mass m = mass in kg (1 amu = 1.6605 x 10 –27 kg) c = speed of light (2.9978 x 10 8 m s -1 ) 14 7 N 7 1 1 H + 7 1 0 n E = N. B. E. N. B. E. = Energy required to separate nucleus of atom into protons and neutrons.
Background image of page 8
Question # 4 a. 1.0 x 10 16 J b. 3.4 x 10 7 J c. 1.7 x 10 -11 J d. 5.6 x 10 -20 J What is the N. B. E of 14 7 N per nucleus? 14 7 N 7 1 1 H + 7 1 0 n E = N. B. E. m = 0.1123 amu 1 amu = 1.66 x 10 –27 kg c = 3.00 x 10 8 m s -1
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Question # 4 a. 1.0 x 10 16 J b. 3.4 x 10 7 J c. 1.7 x 10 -11 J d. 5.6 x 10 -20 J What is the N. B. E of 14 7 N per nucleus? 14 7 N 7 1 1 H + 7 1 0 n ΔE = N. B. E. m = 0.1134 amu 1 amu = 1.66 x 10 –27 kg c = 3.00 x 10 8 m s -1 m = 0.1123 amu x 1.66 x 10 -27 kg/1 amu = 1.86 x 10 -28 kg E = 1.86 x 10 -28 kg x (3.00 x 10 8 m s -1 ) 2 = 1.67 x 10 -11 kg m 2 s -2 = 1.67 x 10 -11 J N.B.E. = 1.7 x 10 -11 J/nucleus
Background image of page 10
First order radioactive decay 6 h 6 h 6 h 6 h t 1/2 = 6 h
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Pu-239 half-life is 24,000 years. How much plutonium-239 remains in a sample that initially contained 1.0 kg of plutonium after 96,000 years? a. 1/2 kg b. 1/4 kg c. 1/8 kg d. 1/16 kg Question #5
Background image of page 12
Example How long will a cobalt–60 source be useful if it can be used until the gamma rays it produces reach 70 percent of the original intensity? 60
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 14
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 67

REV09 - CHM 115 Review Final Exam: May 4th 2009 Elliot Hall...

This preview shows document pages 1 - 14. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online