+ atoms, ions, and isotopes oh my!. + es/documents/evolutionofatomicmodel.pdf
TRANSCRIPT
+
Atoms, Ions, and IsotopesOh my!
+
http://www.projectsharetexas.org/sites/default/files/resources/documents/EvolutionOfAtomicModel.pdf
+Name that component!
Has a negative charge
Has a positive charge
Has no charge
Has a relative mass (to proton) of 1
Has an actual mass of 1.67x10-24
Has an actual mass of 9.11 x 10-28
+Objectives for Today
Characterize protons, neutrons, electrons by location, relative charge, relative mass (p=1, n=1, e=1/2000).
• Use symbols: A= mass number, Z=atomic number
• Use notation for writing isotope symbols:235 92 or U-235
• Identify isotope using mass number and atomic number and relate to number of protons, neutrons and electrons.
• Differentiate average atomic mass of an element from the actual isotopic mass and mass number of specific isotopes. (Use example calculations to determine average atomic mass of atoms from relative abundance and actual isotopic mass to develop understanding)
+How will we do that?
Group read and presentation
Everyone takes notes on presentation
I recap anything necessary
Significant Figures and Scientific Notation
Introduce Electron shells
Discuss Uranium and the nuclear bomb
+Elements on the periodic table
+Elements
Distinguished by atomic number Atomic number correlates with number of protons Therefore an atom is defined by its number of protons
Therefore an atom is unique by its positive charged elements
Have a variable mass Number of neutrons can change (will get into this
more later)
Have a variable charge Number of neutrons can change (ibid.)
+Calculating things with elements
The number of neutrons in an atom is the difference between the mass number and atomic number
# of Neutrons = Mass # - atomic #
+Isotopes
Atoms with the same number of protons but different number of neutrons Therefore, mass changes, charge changes
Hydrogen isotopes Hydrogen – 1 (Hydrogen) Hydrogen – 2 (deuterium) Hydrogen – 3 (tritium)
What happens when we add a fourth neutron?
+Atomic Mass Units
Reference Isotope is Carbon – 12
Has six protons, six neutrons and one amu is equal to
Mass of carbon-12 divided by 12 (presumably an approximation of the mass of a proton or neutron)
+Overall amu
To calculate the atomic mass of an element, multiply the mass of each isotope by its natural abundance, expressed as a decimal and then add the products
+Groups
Difference between atomic number and mass number
Isotopes
Atomic mass unit and natural abundance
Preview of periodic table
+Catalyst 9/16
Collect one of each handout on table
Hole punch them if you need to
Then be seated by the time the bell rings.
+Objectives
Understand what an ion is
Analyze diagrams related to the Bohr model of the hydrogen atom in terms of allowed, discrete energy levels in the emission spectrum.
• Describe the electron cloud of the atom in terms of a probability model.
• Relate the electron configurations of atoms to the Bohr and electron cloud models.
Become familiar with the math of science
+To accomplish these we will
Take some notes
Do a demonstration
Complete several work sheets on the science of math
+
https://www.youtube.com/watch?v=WWc3k2723IM
https://www.youtube.com/watch?v=thnDxFdkzZs
Then Carbon as an example
+Bohr Model
+
+Probability Model
Describes the areas around the nucleus in which we are likely to find the electrons, depending on their energy level and element.
+
+Activity
+Catalyst 9/17
Review: Name the properties (relative mass, charge, location) of an
electron, proton, and neutron What happens when the number of protons changes?
Neutrons? Electrons?
The atomic mass listed on the periodic table is the average atomic mass. In order to calculate it, we need to know what isotopes exist, and their natural abundance. Use words or a formula to state how we calculate average atomic mass
What are some difference between the Bohr Model and the Electron Cloud (Probability Model)?
+But first, let me talk about ions
https://www.youtube.com/watch?v=WWc3k2723IM
Don’t overthink this:
Se3+ refers to an ion with a positive 3 chargeTherefore is missing 3 electrons
+Electron Configurations
Bohr model indicates seven energy levels
Electron Cloud/Probability Model indicates seven levels, but up to (and maybe more) four sublevels These are s, p, d, f They look pretty crazy
You need to know 3 principles of calculating Aufbau Principle Pauli Exclusion Principle Hund’s Rule
+Aufbau
Electrons fill lowest available energy shells first
S then p then d then f, until the third orbital 4s happens
before 3d
3
+Pauli Exclusion Principle
Each orbital can contain two electrons
Each electron has a positive or negative spin These are written as and
Pauli Exclusion Principle
Electrons first fill every available empty orbital before taking a negative spin next to a positive electron
+Quanta
A unit of energy
When energy is applied to an atom, the electrons move from a lower/ground state to an excited state
When energy is released from the atom, an electron goes back down to ground state and the energy takes the form of EM wave discharge
+Significant Figures
http://www.usca.edu/chemistry/genchem/sigfig.htm
+Catalyst 9/24
Please take one sheet of paper. Keep it face down. We’ll get to it later
There are a number of different articles; yours may not be the same as your neighbors. That’s fine.
Actually, it’s not that fine. You shouldn’t know what your neighbor has because you shouldn’t have turned it over.
After announcements we’ll have a few test questions to go over. Have your note sheets ready.
Turn the packet in to the bin at the front.
+
+What pieces of information would help you answer this question?Write down any strategies you can use to answer the question.
+
+Objectives Articulate that this electromagnetic radiation is given off as photons.
• Understand the inverse relationship between wavelength and frequency, and the direct relationship between energy and frequency.
• Use the “Bohr Model for Hydrogen Atom” and “Electromagnetic Spectrum” diagrams from the Reference Tables to relate color, frequency, and wavelength of the light emitted to the energy of the photon.
• Explain that Niles Bohr produced a model of the hydrogen atom based on experimental observations. This model indicated that:
1. an electron circles the nucleus only in fixed energy ranges called orbits; 2. an electron can neither gain or lose energy inside this orbit, but could move up or down to another orbit; 3. that the lowest energy orbit is closest to the nucleus.
• Describe the wave/particle duality of electrons.
+Homework
Finish any homework or assignments that you need to finish
Turn these in tomorrow morning!!!!!!!!!!!!!!!
Stay tuned for a wardrobe request
+
+On light, and color
http://web.archive.org/lessons/how-do-we-see-color-colm-kelleher#review
+Before reading…
Group A: List everything you know about particles
Group B: List everything you know about waves
Group C: List everything you know about light
Read and annotate the article What evidence does the author present? What are some things the author doesn’t consider?
+Next:
Groups get together: collect and refine evidence for your view of the electron
Each group presents their view of the electron
+
http://phys.org/news/2015-03-particle.html
+Homework:
Group A: wear green
Group B: wear blue
Group C: wear red
This is for bonus points on your next quiz
+Catalyst 9/25
Take out the worksheets related to “Electron Configuration” that I gave last week.
Turn in any overdue homework
All this is done silently
Start looking over all the questions. Start by checking off which ones you feel you cannot answer. Circle those, and on the index card, write what information you’ll need to solve them.
Then answer the ones you feel you know.
+Objectives/Plan for today
Understand electron configuration as modeled by the Bohr and Electron Cloud model
Understand light
Prepare for review for Tuesday Quiz
+Catalyst 9-28
Write out the Orbital Notation and Electron Configuration for Iodine
Iodine-127 is the most stable and common isotope for the element. What is the atomic mass of Iodine-127?
How many protons are in Iodine 127? How many neutrons?
Given that the Periodic Table shows Iodine with an atomic mass of 126.90, what does this say about the natural abundance of Iodine 127?
+Objectives
Understand Bloom’s Revised Taxonomy
Review material from this objective
Create study guides for further review
Prepare for quiz tomorrow
+Bloom’s Taxonomy applied
+Your study guide
Must address all objectives
Can be no more and no less than 12 questions
One question should be an exploration of a certain element, as demonstrated in the catalyst This element must be in the fourth period or below
Should have a question that applies each of the bottom four levels of Bloom’s Revised Taxonomy
Bonus points for each additional objective covered in the same question and each additional level of thinking (Bloom)
Group with the most points gets a bonus point on the quiz