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Name___________________________________ Per. ______

Atomic Structure/Nuclear Chemistry (Ch. 3 & 21)

OTHS Academic Chemistry Objectives: Understand the experimental design and conclusions used in the development of modern atomic theory,

including Dalton's Postulates, Thomson's discovery of electron properties, Rutherford's nuclear atom, and Bohr's nuclear atom

Use isotopic composition to calculate average atomic mass of an element

Describe the characteristics of alpha, beta, and gamma radiation

Describe radioactive decay process in terms of balanced nuclear equations

Compare fission and fusion reactions.

Vocabulary: Isotope, average atomic mass, radio-isotope, daughter nucleus, fission, fusion, half-life, isotope, nuclear energy, nuclear reactions, nuclear sources, nuclear waste, radiation, transmutation, positron

Topics to review: Atomic Structure

Scientists & contributions to atomic theory

Current atomic theory

Subatomic particles

Ion vs isotope

APE MAN calculations

Average atomic mass calculations

Nuclear Chemistry

Alpha & beta decay

Alpha, beta, gamma penetrance

Fission vs Fusion

Half Life Calculations

CHECKLIST: How to be successful in OTHS Academic Chemistry Pay attention and take notes in class Ask questions in class on material that is not clear Work every page in the practice packet for the unit Check answers to the practice packet online at http://othschem.weebly.com/ Come to tutorials with any chemistry teacher Do the online homework and check solutions once they become available Always do the practice test for every test & ask good questions on review day Keep up with the calendar for the class/be aware of approaching quizzes, tests, & other deadlines Use videos posted on website as a quick and convenient tutorial Read the chapter in the book

Memorize: Provided: A=P=E M-A=N

Alpha particle

Beta Particle

Periodic table

Name __________________________ Per. ____

Atomic Structure Worksheet Helpful information: Isotopes are two or more forms of an element that differ only in the number of neutrons. Atomic number is equal to the # of protons, which is the same as the # of electrons in any neutral atom (not an ion). The atomic number is found on the periodic table; it’s the whole number. It defines each element. Mass number is equal to the # of protons + the # of neutrons (p + n) The mass number is different for each isotope of an element. It is obtained from the notation in the element or symbol. For example: Carbon-13: mass number is 13 13 6 C : mass number is 13 (top # is the mass number, bottom # is the atomic number)

Isotope Symbol Atomic Number

Mass Number

# of p+ # of no # of e-

Uranium-235

3 1 H

2 1 H

1 1 H

29 14

7 7

56 26

Potassium-41

208 82 Pb

81 35

38 50

23 11

Argon-40

19 9 F

32 16

29 34

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Atomic Structure Worksheet Part II: Average Atomic Mass Atomic mass is the average mass of one atom of an element, in amu. The atomic mass is found on the periodic table; it is the number with the decimal places. Atomic mass is calculated by performing a weighted average of the masses of all isotopes of an element. 1. Determine the average atomic mass for each of the following elements, given each isotope’s mass and percent abundance. Check your answers on the periodic table.

a. Oxygen, composed of oxygen-16 (mass 15.99 amu and 99.8%), oxygen-17 (mass 17.00 amu and 0.04%), and oxygen-18 (mass 18.00 amu and 0.2%)

b. Silver, composed of silver-107 (mass 106.91 amu and 51.8%) and silver-109 (mass 108.90 amu and 48.2%)

c. Neon, composed of neon-20 (mass 19.99 amu and 90.51%), neon-21 (mass 20.99 amu and 0.27%), and neon-22 (mass 21.99 amu and 9.22%)

2. Determine the average atomic mass for this unknown element, and then use the periodic table to identify the element: Isotope #1 has mass 34.97 amu and % abundance 75.77%. Isotope #2 has mass 36.97 amu and % abundance 24.23%. The element is: __________ 3. Boron has 2 isotopes: boron-10 (mass 10.0 amu) and boron-11 (mass 11.0 amu). Look up the average atomic mass of boron on the periodic table: __________ Find the percent abundance of each isotope. Hint: Call the relative abundance for one isotope x, and then the relative abundance of the other isotope is 1-x.

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Nuclear Chemistry Pre- Test

True or False?

1. _____ Home smoke detectors contain radioactive materials.

2. _____ Radioactive materials and radiation are unnatural; they did not exist on Earth until created by scientists.

3. _____ All radiation causes cancer.

4. _____ You can get cancer from a microwave.

5. _____ Human senses can detect radiation.

6. _____ Individuals vary widely concerning how they are affected by exposure to

radiation.

7. _____ Small amounts of matter change to immense quantities of energy released by

nuclear weapons.

8. _____ Physicians can distinguish cancer caused by radiation exposure from cancer

resulting from other causes.

9. _____ Medical x-rays are dangerous.

10._____ Nuclear power plants create serious hazards to public health and to the environment.

11._____ An improperly operated nuclear power plant can explode like a nuclear

weapon.

12._____ Some nuclear wastes must be stored for centuries to prevent dangerous

radioactivity from escaping.

13._____ New dangerous elements are being invented every day.

14._____ Nuclear power plants produce material that can be converted into nuclear weapons.

15._____ All nuclear medical techniques are highly dangerous.

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Name: _____________________________ Period: _______ Alpha and Beta Decay Reactions Practice

Write a balanced equation for each of the following nuclear reactions. Example Chlorine-36 decays by beta emission. Dubnium-262 decays by alpha emission eArCl 0

13618

3617 −+→ HeLrDb 4

2258103

262105 +→

1. Krypton-87 decays by beta emission.

_______________________________________________________

2. Curium-240 decays by alpha emission.

_______________________________________________________

3. Uranium-232 decays by alpha emission.

_______________________________________________________

4. Silicon-32 decays by beta emission.

_______________________________________________________

5. Zinc-71 decays by beta emission.

_______________________________________________________

6. Americium-243 decays by alpha emission.

_______________________________________________________

7. Cobalt-60 decays by beta emission.

_______________________________________________________

8. Phosphorus-32 decays by beta emission.

_______________________________________________________

9. Gadolinium-150 decays by alpha emission.

_______________________________________________________

10. Lead-210 decays by emitting both a beta and an alpha particle.

_______________________________________________________

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Name: _____________________________ Period: _____

Radioactive Decay Series Using the information given here as well as the periodic table and your knowledge of alpha (α) and beta (β) decay reactions complete each of the following. a. Label each reaction as an alpha or beta decay on the blank in front of the number. b. Complete each reaction and use your answer from one reaction as the reactant for the

next step. This is the decay series of Uranium-238.

_____ 1. Th HeU 234

9042

23892 +→

(a)

_____ 2. PaeTh 23491

01

23490 +→−

(a) (b)

_____ 3. + _______ →− ePa 01

23491

(b) (c)

_____ 4. ______ + _______ → He42

(c) (d)

_____ 5. ______ + _______ → He42

(d) (e)

_____ 6. ______ + _______ → He42

(e) (f)

_____ 7. ______ + _______ → He42

(f) (g)

_____ 8. ______ + _______ → He42

(g) (h)

_____ 9. ______ + _______ →− e01

(h) (i)

_____ 10. ______ + _______ →− e01

(i) (j)

_____ 11. ______ + _______ → He42

(j) (k)

_____ 12. ______ + _______ →− e01

(k) (l)

_____ 13. ______ + _______ →− e01

(l) (m)

_____ 14. ______ + _______ → He42

(m) (n)

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Half-life Worksheet

Fill in the missing information; show work below using either the formula or the chart method. Time units in first 2 columns must match! Convert when necessary.

Half-life Elapsed time Initial amount Amount remaining 1. 90 min. 6 hours 3000 mg 2. 300 years 600 years 27.6 g 3. 9 months 3 years 10,000 g 4. 1 year 1 year 5246 g 5. 235 years 705 years 20 g 6. 35 years 140 years 10 g 7. 800 years 1600 g 100 g 8. 18 hours 3 days 500 g 9. 5 min. 30 min. 640 g 10. 2000 years 6000 years 8000 g 11. 23 hours 92 hours 12,000 g 12. 90 s 6 min. 3 g 13. 7 years 49 years 1 g 14. 8 billion years 1000 g 250 g 15. 2 hours 5820 g 2910 g 16. 2000 years 640 g 20 g 17. 4 days 2800 g 700 g 18. 4 hours 1 day 600 g

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