Tuesday, March 2, 2010

Eighth Grade Week 19

We leave the natural resources concepts of the Changing Earth and Earth's Waters units, and focus our attention on the integrated concept of change throughout the units. In the Chemical Interactions unit we will look at how things change on the smallest of levels.

What is the structure of an atom?
How does this structure lead to some elements forming ions?

This weeks contract has you select a unique element from the periodic table and design a model of its structure. I will have one question when you present. How does the structure of the element affect its function? Good luck, and pick a winner fast before someone else does.

20 comments:

Delfina said...

Bromine's atomic # is 35. The electronical structure is 2, 8, 18, 7. Mr.Hoopman, does this mean in the first shell, there are 2 electrons, second shell, 8 and so on?

John said...

How electrons behave in an atom is described by an orbital which determined by three math variables we call quantum numbers.

the principal quantum number (n) is a positive interger that tells the size and energy level (ex 1, 2, 3, 4...)

the angular-momentum number (l) tells the shape of the orbital and can be from 0 up to n - 1

the magnetic quantum number (Ms)tells how the orbitals are arranged in space and can be an integer from -l to +l

so, things with one shell in period one have a n = 1 so a l = 0 and a Ms = 0....SO, electrons travel in one shape with no varied orientation - a sphere.

an n value of 2 would get you two possible l values. One, as above, with a value of 0 so an Ms value of 0 so a sphere. However, it also gives a value of 1 (remember, l can equal up to a value of n -1). So, Ms here would be -1, 0, and 1. 3 orbitals arranged in space along 3 axes. They look like figure 8's along the x, y, and z axes.

John said...

Your Bromine is in period 4. SO, n = 4 and l = 0, 1, 2, and 3. So it COULD have have an outer layer with n=1; l=0,1,2,3; Ms=0(sphere) and -1,0,1(three figure 8's) AND -2,-1,0,1,2 (five 4 leaf clover shapes) AAAAAANNNNNNNDDDDD -3,-2,-1,0,1,2,3 (7 8 lobed..things)

That is possible, but in reality it has 4 layers of spheres, 3 layers of three figure 8s, 1 layer of five four leaf clover shapes)

pania said...

why is learning chemistry important? CHEMISTRY IS CONFUSING SOMETIMES I DONT EVEN KNOW WHAT THE numbers or letters or symbols mean.

John said...

Because.

Science is fun.

Pania,

When earthquakes tear open the earth, and tsunamis inundate the land, and meteors fill the sky with fire, all while we get the plague...knowing chemistry will help. Trust me.

It could also be because all things are made up of these chemicals and we depend on their interactions for everything.

It is confusing, I admit, it's like another language. MY wordy answer above is just an attempt to see if anyone can figure it out and give the class a model ot their element that is more than styrofoam on wire rings.

Steven blend said...

Can humans move electrons from one atom to another?

nmueller said...

So the neutrons and protons are the atomic mass number?

nmueller said...

Why do atoms explode when you split them in half.

Unknown said...

why are atoms so explosive

Jack said...

so if an atom shares it electrons does that mean that it is now completed?

ebbottbaby said...

what causes charges in quarks, if they cause charges in elctrons?

Brad said...

How do we know how many elements there are in the world.

Brooke said...

Do you think that more elements will be found?

Brook said...

Mr hoopman why is all this so cunfusing?

Mark said...

pania,
the one on the top is how many protons there are. each element has one more than the last. the letter/letters are the element's symbol, two letters from its name or from its derivation. the number on the bottom is how much each atom weighs, or atomic mass. it is usually a little more than the atomic number times two, due to the fact that there is often one neutron for every proton, and electrons to slightly add to the weight.

Mark said...

jack,
it means that it is now an ion because it has a different number of electrons, but yes, it won't want any more electrons than 8.

Mark said...

nathan,
when you split an atom, the protons/neutrons often fly everywhere, sometimes coming together to form different elements, and the movement of protons/neutrons flying everywhere causes rapid energy release.

John said...

Jack

Yes, the spend time in each atom's valence shell.

Mark,
atomtic mass is a bit more then x2 for the averaging in of isotpe mass.
there are ionic bonds and there are covalent bonds as well

Randy said...

Nathan, atoms don't really explode they split. Radioactive atoms are the only atoms that can split and when they are split the atom turns from mass to energy (E=MC^2). One atom splitting doesn’t cause much energy by itself and wouldn't really do anything. However, when one of these atoms is near other atoms of its type the pieces ricochet off of each other and cause nuclear fission. This process creates a large amount of energy in the form of heat that simply vaporizes everything within a certain area around the site where the reaction started. This is basically what is happening in a nuclear bomb and in nuclear power plants. The only difference between nuclear bombs and power plants is that in power plants people control the rate of fission to produce useable energy.

THomas Theisen said...

What is the difference between a metallic bond and a covalent bond.