Forensic Archaeology Lab

In class today, we began the archaeology lab to research half life. All we got to do today was cut out the 567 squares that represented atoms of the radioactive remains taken from the skeleton that was found by deer hunters. In a quiet town in South Carolina, they stumbled across the skeletal remains and are teaming with archaeologists to found out the mystery. All in all, we are researching the rate at which the body decayed to see the approximate time she was killed. Here is a picture of the 567 squares we cut out!

Beanium Lab

In class today, we conducted a lab with a made up atom called Beanium. We had 4 different isotopes (red, black, white, pinto). The number of atoms in each isotope, total mass of the isotopes, average mass of the isotope, and the percent abundance were all found.

Here is our data table:

Isotope	# of atoms of this isotope present	Total mass of all the atoms of this isotope	Avg. mass of this isotope	% abundance of this isotope
White beanium	79	23.33 amu	.295 amu	40.9%
Black beanium	60	11.88 amu	.198 amu	31.3%
Red beanium	39	13.85 amu	.355 amu	20.2%
Pinto beanium	15	5.17 amu	.345 amu	7.78%

And here is a picture of Kendall doing the lab and sorting out the different "isotopes" :)
Here is a helpful link if you're lost on how to calculate all this: http://www.chemteam.info/Mole/AvgAtomicWt-Reverse.html

Info on the Subatomic Particles

The three subatomic particles in an atom are protons, neutrons, and electrons.

Relative masses:

• proton = 1 amu
• neutron = 1 amu
• electron = 1/1840 amu

Protons give an element its identity and mass

Electrons give an element its reactivity

Neutrons give an element its isotope

A helpful website that breaks this down further is http://chemwiki.ucdavis.edu/Physical_Chemistry/Atomic_Theory/The_Atom/Sub-Atomic_Particles 

Law of Constant Composition

The Law of Constant Composition merely states that all compounds of the same species are always made of the same things and therefore yield the same percent composition/proportion by mass. This basically means that in any single compound containing the same elements, the percentage of composition for each element is the exact same in all of these compounds.

A video that illustrates this fact is found here: http://www.youtube.com/watch?v=2nAYSy8N_x0.

Current Atomic Model

The current model of an atom has been long researched and has taken several contributing scientists and their research. These scientists include Thompson, his student Rutherford, and Dalton's theory of course.

JJ Thompson discovered that something had a negative charge in atoms contained in positively charged matter which were later found to be the electrons. His model is often described as "the cookie model" because what he envisioned resembled a cookie.


Rutherford was Thompson's student who continued his research of atomic structure. He further proved the presence of a positive charge in the center of an atom, which are the protons that are contained in the center structure called the nucleus.


These two major findings contributed to the current atomic model, which is called the cloud model.


A helpful website to understand the current atomic model and its complete evolution is at http://www.projectsharetexas.org/sites/default/files/resources/documents/EvolutionOfAtomicMode.l.pdf

Dalton's Atomic Theory

The first thing we learned in this unit is Dalton's Atomic Theory. He was the first scientist to look into atoms, and he did not know anything of the structure (electrons, protons, nucleus, etc). Although this is true, he constructed 5 theories about atoms that mostly still hold true today--besides one.

1. all elements are composed of atoms
2. atoms of a given element are identical (this is the one that was later found to be false)
3. atoms of different elements are different
4. compounds contain atoms of different elements
5. atoms are indivisible and aren't created or destroyed in chemical reactions (partially true)

A website that elaborates on Dalton's theory is http://dl.clackamas.edu/ch104-04/dalton's.htm.

Entry #2 Nomenclature- Naming Acids

Another method of naming in Nomenclature is naming acids. There are a few obstacles to remember, and again, this diagram helps visually sort that out.

*NO O = HYDRO*
*-ITE = -OUS*
*-ATE = -IC*

Entry #1 Nomenclature- Naming Type 1, 2, & 3

Below is a diagram that I found useful from our textbook to organize the ways of naming binary compounds. This is helpful for all of the visual learners that like flowcharts and diagrams to organize things in their head!