Atomic Structure

Chemistry Assessment

Eligible Texas EssentialKnowledge and Skills

Texas Education AgencyStudent Assessment DivisionSeptember 2010

Readiness standards have the following characteristics.

• They are essential for success in the current grade or course.

• They are important for preparedness for the next grade or course.

• They support college and career readiness.

• They necessitate in-depth instruction.

• They address broad and deep ideas.


Supporting standards have the following characteristics.

• Although introduced in the current grade or course, they may be emphasized in a subsequent year.

• Although reinforced in the current grade or course, they may be emphasized in a previous year.

• They play a role in preparing students for the next grade of course but not a central role.

• They address more narrowly defined ideas.


TEA is implementing a number of changes that should serve to test knowledge and skills in a deeper way.

• Tests will contain a greater number of items that have a higher cognitive complexity level.

• Items will be developed to more closely match the cognitive complexity level evident in the TEKS.

• In science, process skills will be assessed in context, not in isolation, which will allow for a more integrated and authentic assessment of these content area.

• In science, the number of open-ended (griddable) items will increase to allow students more opportunity to derive an answer independently.


Atomic Structure

(6) Science concepts. The student knows that atomic structure is determined by nuclear composition, allowable electron cloud, and subatomic particles. The student is expected to:

(A) describe the existence and

properties of subatomic particles

(B) analyze stable and unstable isotopes of an element to determine the relationship between the isotope's stability and its application

(6) Science concepts. The student knows and understands the historical development of atomic theory. The student is expected to:

(A) 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 Supporting

(B) understand the electromagnetic

spectrum and the mathematical relationships between energy, frequency, and wavelength of light Supporting

(6) Science concepts. The student knows that atomic structure is determined by nuclear composition, allowable electron cloud, and subatomic particles. The student is expected to:

describe the existence and properties of subatomic particles

(B) analyze stable and unstable isotopes of an element to determine the relationship between the isotope's stability and its application

(C) calculate the wavelength, frequency, and energy of light using Planck's constant and the speed of light Supporting

(D) use isotopic composition to

calculate average atomic mass of an element Supporting

(E) express the arrangement of

electrons in atoms through electron configurations and Lewis valence electron dot structures Readiness

CCRS – Atomic StructureSummarize the development of atomic theory. Understand that

models of the atom are used to help understand the properties of elements and compounds.

Describe the discoveries of Dalton (atomic theory), Thomson (the electron), Rutherford (the nucleus), and Bohr (planetary model of the atom); understand how each discovery contributed to modern atomic theory.

Identify the masses, charges, and locations of the major components of the atom (protons, neutrons, and electrons); describe Rutherford’s “gold foil” experiment that led to the discovery of the atomic nucleus; and describe Millikan’s “oil drop” experiment that led to determining the charge on an electron.

CCRS – Atomic Structure

Describe basic wave properties (calculate wavelength, frequency, or energy of light) and understand that electrons can be described by the physics of waves.

Explain the importance of quantized electron energy and its relationship to atomic emission spectra.

Understand the electron configuration in atoms (Aufbau principle, the Pauli exclusion principle, Hund’s rule) and their connection with the periodic table

Prior Knowledge

• Metric conversions

• Solving literal equations

• ROYGBIV

• Subatomic particles’ and their properties

• Direct and inverse relationships

Engage – prior knowledge

Think – pair – share with previous knowledge of the atom

Use that to discuss the properties and location of the subatomic particles.Representing the composition of an atom with symbols and names.Isotope vs. ion

History of the Atom

Balance - quantitativeDalton – atomic postulatesCathode ray tube –

Thomson – e-

Radioactivity – gold foil Rutherford - nucleus

Bright line spectra – Bohr model

Which principle of Dalton’s atomic theory did Thomson disprove?

A.Different atoms have different masses.B.All atoms of the same element have the

same mass.C.Compounds always have the same percentage

composition by mass.D.Atoms are indivisible.E.Atoms can be combined to make compounds.

Rutherford’s experiment disclosed which of the following about the atom?

A.Electrons orbit outside the nucleus.B.The alpha particles are NOT affected by the

nucleus of an atom.C.The atom has electrons and protons equally

dispersed.D.The nucleus is positive, dense, and small.E.The atom contained neutrons.

Low Frequency High Frequency

Long

Wavelength

Short

Wavelength

Visible Light

Electromagnetic Spectrum

700 nm 600 nm 500 nm 400 nm

Radiowaves Microwaves Infrared Ultraviolet X rays Gamma rays

Low Energy High Energy

Wavelength and frequency are inversely related. c = n l

Energy and frequency are directly related.

E = h n

Bright Line Emission Spectra

Passing an element’s emission spectrum through diffraction grating sorts the spectrum into discrete frequencies or lines.

Every element’s spectrum is unique.

H

He

Ne

Cool Bohr model – emission spectrum animation can be found at:

http://www.youtube.com/watch?v=8TJ2GlWSPxI&feature=related



l = ? n = 5.10 X 1014Hzc = 3.00 X 108 m/s

c = n l E = h n

What is the frequency for light with a wavelength of 5.00 X 10 -5 cm?

E = ? n = 6.66 X 1014 1/sh = 6.626 X 10-34 J s

c = n l E = h n

How much energy is released if a bright line has a frequency of 8.22 X 1013 Hz?

If electromagnetic radiation A has a lower frequency than electromagnetic radiation B, then compared to B, the wavelength of A is

A. longerB. shorterC. equalD. cannot be determined

Mass Number vs Atomic Mass

Students use atomic number, mass number and atomic mass indiscriminately

Quick intro activity to atomic mass:– 2 bags 9 p+ 8 no

– 3 bags 9 p+ 11 no

– 21 bags 9 p+ 10 no

18.96 amu

Atomic Mass

(% isotope1) ( mass of isotope1) (% isotope2) ( mass of isotope2)

+ (% isotope3) ( mass of isotope3)weighted average

think …6 weeks

grade

The fictional element Kryptonite (let’s give it the symbol Ky) associated with Superman’s home planet of Krypton could be said to consist of two isotopes kryptonite-285 (70%) and kryptonite-289 (30%). Estimate the approximate atomic mass of kryptonite.

A. 288 amuB. 287 amuC. 286 amu D. 285 amu

s orbital 2 e-

p orbital 6 e-

d orbital 10 e-

f orbital 14 e- through Kr

Write the electron configuration for potassium

1s22s22p63s23p64s2

# of valence electrons?

dot diagram?

group and period?

Relate configuration and valence electrons to periodic table location

If the outer electron configuration of an element is 2s1, the element below it on the periodic table will have an outer electron configuration of _______.

A. 2s2

B. 3s1

C. 2s22p6

D. 3s2

E. 1s2

Periodic Table

(4) Science concepts. The student knows the characteristics of matter. The student is expected to:

(D) describe the physical and

chemical characteristics of an element using the periodic table and make inferences about its chemical behavior.

(5.C) summarize the historical

development of the periodic table to understand the concept of periodicity.

(5) Science concepts. The student understands the historical development of the Periodic Table and can apply its predictive power. The student is expected to:

(A) explain the use of chemical and physical

properties in the historical development of the Periodic Table Supporting

(B) use the Periodic Table to identify and

explain the properties of chemical families, including alkali metals, alkaline earth metals, halogens, noble gases, and transition metals Readiness

(C) use the Periodic Table to identify and

explain periodic trends, including atomic and ionic radii, electronegativity, and ionization energy Readiness

CCRS

1. Know the organization of the periodic table. Identify periods and groups on the periodic table. a. Identify metals, metalloids, and non-metals on

the periodic table. b. Distinguish between and describe patterns in

electron configurations for representative elements, transition elements, inner-transition elements, and noble gases. Predict the common charges on the representative elements from the periodic table.

CCRS

2. Recognize the trends in physical and chemical properties as one moves across a period or vertically through a group.

a. Define and describe the periodic trend: atomic radii, ionic radii, ionization energy, electron affinity, and electronegativity.

b. Use the periodic trends to compare the size and behavior of atoms and ions.

Prior Knowledge

• Identify physical and chemical properties

• Identify metals and nonmetals and their

properties

• Identify special groups and regions of the

table

• Identify number of protons, valence electrons

Periodic table

after electron

configuration

Historical Development• Mendeleev – grouped by chemical

properties – in order of atomic weight – left spaces and predicted properties for undiscovered elements

• Moseley – in order of atomic number

Students should perform some activity in which they emulate Mendeleev’s process

Decreasing atomic radius Increasing ionization energy Increasing electronegativity

Incr

easi

ng a

tom

ic ra

dius

Dec

reas

ing

ioni

zatio

n en

ergy

Dec

reas

ing

elec

tron

egati

vity

Periodic Trends

Down groups• More energy levels• Greater shielding

effect• Greater distance

between nucleus and valence electrons

Across periods• Increasing effective

nuclear charge• Greater attraction

for valence electrons

Which of the following groups of elements have similar chemical

reactivity?

A. Li, Be, C

B. Be, Mg, Sr

C. Sc, Y, Zr

D. C, N, O

When a metal atom combines with a nonmetal atom, the nonmetal atom will

A. lose electrons and decrease in size

B. lose electrons and increase in size

C. gain electrons and decrease in size

D. gain electrons and increase in size

Atoms of elements in a group on the Periodic Table have similar chemical properties. This similarity is most closely related to the atoms'A. number of principal energy levels B. number of valence electrons C. atomic numbers D. atomic masses

Which of the following does NOT affect the ionization energy of an element?

A. the distance of the electrons from the nucleus

B. the number of energy levels in the atomC. the number of neutrons in the nucleusD. the charge of the nucleus

Nuclear Chemistry

TEKS(9) Science concepts. The student knows the

processes, effects, and significance of nuclear fission and nuclear fusion. The student is expected to:

(A) compare fission and fusion reactions in terms of the masses of the reactants and products and the amount of energy released in the nuclear reactions

(B) investigate radioactive elements to

determine half-life (C) evaluate the commercial use of nuclear

energy and medical uses of radioisotopes (D) evaluate environmental issues associated

with the storage, containment, and disposal of nuclear wastes.

(12) Science concepts. The student understands the basic processes of nuclear chemistry. The student is expected to

(A) describe the characteristics of alpha, beta, and gamma radiation Supporting

(B) describe radioactive decay process in terms of balanced nuclear equations Readiness

(C) compare fission and fusion reactions Supporting

CCRSUnderstand radioactive decay.

a. Identify the types of radioactive decay particles that occur, compare their properties (e.g., mass, charge, composition, penetrating ability), and write equations representing the decay processes.

b. Explain the concept of half-life for a radioisotope, and use this concept to determine the amount of a certain sample of radioisotope remaining after a period of time, given the length of the half-life.

c. Determine the length of time that has passed, given the remaining amount of radioisotope, the original amount of radioisotope, and the length of the half-life.

d. Explain how carbon-14 is used to date artifacts. e. Compare and contrast the nuclear processes of fission and

fusion.

Prior Knowledge

• Atomic number

• Mass number

• Isotopic notationU234

92

Characteristics of RadiationAlpha Beta gamma

Charge + - 0

Relative mass

4000 1 0

Symbol

Stopped by Paper or skin

Aluminum or plastic

Lead or concrete

αHe 42

42 βe 0

1-01- γ0

0

Nuclear Chemistry

Fill in the missing particle

Write a nuclear equation for the beta decay of sulfur-35

U_______Pu 23492

23894

Fission• Splitting larger atoms

into smaller• Is initiated with

neutrons• Can be controlled

with Cd rods• Produces radioactive

waste• Uranium-235 is

primary fuel source

Fusion• Putting smaller

atoms together to make a larger one

• Requires extremely high temperatures

• Only product is helium – not radioactive

• Produces more energy than fission

Nuclear ChemistryThe diagram below shows the pattern observed when the radiation from a nuclide traveled through charged plates to a photographic film. Which of the diagrams above identifies the type of radiation that was responsible for exposing the film at each of the three locations?

One advantage of a fusion reaction over a fission reaction for producing energy is

that the fusion reaction ___.A. can be produced starting with only a few

neutronsB. produces more energy per particle than

does the fission reactionC. requires only inexpensive uranium metal

as a fuelD. takes place at a normal temperature

Atomic Structure

Education

Transcript of Atomic Structure