4-26

Today in class:

handed back tests from last week - some people need to re-do.

Discussed element name & symbols quiz tomorrow - need to know # 1-20.

Notes on Metals, Ions, and valence electrons, plus a video clip showing off some examples.

Homework: practice WS on isotopes of different elements - finding protons, neutrons, and mass #.

Review stuff

Rats! I promised a TGT Review on here but don't have one made and have to head home. I will instead give you places to study:

The state wants you to be able to describe how changes in a nucleus of an atom results in emission of radiation. This exact idea is one that we won't reach until after break, but we are laying some ground work for this content:

Half lives: Know what a half life is, that they differ for different nuclei, and how to work with them.

On the test I may:

a. give you a half life of a radionuclide (Cs - 137 = 31 years, etc.) and ask you to find percent remaining after x half lives.

b. give you a chart with numbers of atoms of a radionuclide and ask you to determine its half life.

c. give you a graph with numbers or radioactive emissions (like we did in class) and ask you to determine half life

d. ask you to interpret the amount of radioactivity coming from something to how many half lives it's experienced.

Decay modes:

On the test I may:

a. give you a starting radionuclide (U-238, etc.) and tell you it undergoes alpha and then beta decay, etc. and ask you where you end up (decay series)

b. ask you to contrast particles and emissions: alpha, beta, gamma

c. explain how the nucleus changes during an alpha or beta emission

d. relate alpha, beta, and gamma to shielding that we did in lab.

Nuclear Energy:

On the test I may:

a. ask you to explain some pros/cons to nuclear energy

b. ask you to compare / contrast nuclear energy to traditional (coal) electricity production

c. ask you to relate what happens in our power plants to what happens in stars (fission vs. fusion)

Tomorrow we'll review more. I was planning a cool video on the topic we debated today (nuclear power) but I will postpone that until after Wednesday's exam (it's more like a quiz)

4-15 Homework

This weekend: Based on your reading assigned this week, the things you learned in class/lab, and your perceptions from the media, decide if you are For or Against Nuclear power.

(as if we were going to build a new power plant in Arnold based on your vote.)

Back it up with 10 reasons for your stance. They may be:

Facts

Concerns

Opinions

History

4-13

Today in class we finished up the half life lab graphing and sharing of data. Tomorrow holds two labs for us; will be fun and interesting to see how predictions match up to findings.

Homework!!!

Read p. 796-809, p. 810, p. 494-500, and p. 510. Please read all of these by Friday. **You will need it for points on Friday's activity/discussion**

4-11

Today in class we had a practice quiz and went over answers.

Find a copy here.

We also got out geiger meters, found out how they worked, and experimented a bit with radioactive samples.

Tomorrow we'll have an official lab on half-lives.

NEW optional assignment for this unit: Alpha and Beta Decay Simulation May be turned in by next Monday.

ALSO, I'm looking for volunteers to research and present to class. 5 minutes are offered, on the topics of:

How a geiger tube works

Nuclear Fusion - how it gives us energy

Nuclear Fission - how it gives us energy

I'll take one volunteer per class. Present on Friday if you volunteer. This counts as an optional assignment as well, and will accept one person per topic, per class period. First come, first serve.

4-5 & 4-6

4-5 - finish notes on radiation (see previous post) and practice with what happens in alpha and beta decay.

Get tests back (most classes)

Homework: Worksheet on decay / radioactivity

4-6 Today in class: Half Life Simulation - pennies!

determination of number of half lives to get a substance to turn from parent to daughter nuclei. Just because a half life has passed for a particular element does not mean that exactly half of its nuclei will have decayed. Statistically half should.

Today's warm-up: In Beta Decay: Atomic number _______. Atomic Mass ____________. __________ is ejected from the nucleus. (_________ is emitted as well!)

Answers: Increases by 1, remains the same, Beta particle / electron , gamma ray

Tonight's homework: Read p. 791-799

Tomorrow: problems & practice with decay series and half lives / dating Start talking about biology and radiation

4-4

Today in class: Radioactivity! (a bit of an odd jump, but we have some materials coming next week that I have to return afterward).

Reading over the weekend was: p. 786-790.

Tonight: Read p. 584-587.

Today we looked at Isotopes and decay particles involved in nuclear reactions. Notes: here