atomic structure

Orbitals, s, p, d, f and average distance from the nucleus
Orbitals are the regions of space occupied by electrons in atoms. The shapes and volumes of space are different for each type of orbital. The electrons are confined to specific shaped spaces around the nucleus. The electrons are not on the surface of these shapes. The electrons are moving inside the volume marked out by the shape.
The shape for all "s" orbitals is spherical with the center of the sphere at the nucleus. The size of the sphere increases for increasing quantum numbers. The 1s has a smaller diameter than the 2s and so forth.
1s <>

The p orbitals have a double lobe shape with the point of contact of the lobes at the center of the nucleus. The three different p orbitals are each aligned along one of the three coordinate axes x, y, or z.

The principle quantum number "n" is very useful. It tells the relative energy for an electron in an atom and it also indicates the average distance between the nucleus and an electron. The higher the value for "n" the greater the distance between the nucleus and the electron. An electron in the first level, n = 1, is closer to the nucleus on average than an electron in the n = 4 shell. Exercise: What do the subscripts x,y an z indicate about the "p" orbitals in a shell? Click here for answer
Number of orbitals in a shell
The number of each type of orbital has a mathematical origin. You need to know only the results of the math.
orbital type s p d f

maximum number of orbitals in a shell 1 3 5 7

number of electrons that can fit into orbital type 2 6 10 14

Notice that the number of orbitals increases by "2" in going from one type to another. The capacity for electrons increases by "4" at the same time.
Exercise:
How many "g" orbitals would you predict? Answer: There should be 9 and they could hold 18 electrons.

Number of electrons in an orbital and electron spin
Every orbital can only hold two electrons. This is linked to the magnetic character of electrons. The electrons act as though they are spinning charged particles. There are two spin directions that match the two magnetic fields created by electrons. There is a spin up field and a spin down field. Commonly the two magnetic fields and spin types are indicated by arrows. An up arrow for spin up and a down arrow for spin down. The pairing of the magnetic fields of two electrons cancels out the fields and sets the limit on the population of an orbital at two.
Maximum number of electrons in any orbital = 2
Atoms with all the electron spins paired have no magnetic character. An atom with unpaired electrons shows magnetic properties. This is the origin of the magnetic behavior of iron and nickel for example. This magnetic property gives us a way to know how the electrons are arranged in atoms. Particles with unpaired electrons are called as "free radicals". Free radicals have been linked to the aging process, mutations in DNA, and cancer.

Exercise: How many electrons can fit into all of the 3p subshell orbitals? Click here for answer.

atomic structure

Total enegies of an atom: potential energy and kinetic energy.

An unusual feature of electrons and atoms is that the energy is "quantized" or restricted to definite values. This is not what we see on a daily basis with large objects. Big things appear to have continuous energy states, with no restrictions or jumps. The emission spectra of atoms provides the proof of the quantum theory as it applies to atoms and subatomic particles. Every element can be made to emit light that is characteristic for that element. This is consistent with the idea that each element has a unique energy level pattern. The light emitted by an element's atoms matches the possible jumps betweeen energy levels for the electrons in the atoms. The total energy for a specific shell is restricted. The total can be made up of a high kinetic energy(KE) and a low potential energy(PE). Sometimes the KE is low and the potential energy is high. The total is what counts.
Energy total = kinetic energy + potential energy The basic idea is that the electrons in atoms can only have energy values governed by the principle quantum number "n". The principle quantum number can have only positive whole number values. This means no fractions and no negative numbers. The allowed values for "n" are 1, 2, 3, up to infinity. Electrons in atoms typically only use the first seven energy levels.
Number of electrons in a shell or level
The principle quantum number "n" is very useful. It provides a way to dtermine the maximum number of elecytrons that can fit into a shell. The number of electrons that can fit into a shell is given by the following formula.
Maximum number of electrons in level = 2n2
This means that the first shell can hold only two electrons. The second shell with n = 2 can hold only eight, 8, electrons.
Row in periodic table
Shell
2n2
Maximum number of electrons in shell
1
n=1
2(1)2 = 2
2
2
n=2
2(2)2= 8
8
3
n=3
2(3)2= 18
18
Distance between nucleus and an electron
The principle quantum number "n" is very useful. It tells the relative energy for an electron in an atom and it also indicates the average distance between the nucleus and an electron. The higher the value for "n" the greater the distance between the nucleus and the electron. An electron in the first level, n = 1, is closer to the nucleus on average than an electron in the n = 4 shell.
Shells, number of subshells, and order of filling
The shells or energy levels are also divided into sublevels or subshells. The labels for these subshells comes from the observations of light emitted by atoms. The labels for subshells are s for sharp, p for principle, d for diffuse, f for fine. The physical connections end with the f sublevel class. The relative energies for these sublevels are as follows.
s < p < d < f < g < etc.
The value for "n" equals the number of sublevels for a level. This means the first shell or level has only one sublevel. The second level with "n" equal to two has two sublevels. Check the table below to see what happens for big "n" values. Thankfully, the number of electrons (112) in the biggest atom known can be accommodated by using only the common s, p, d, and f sublevels. The subshells g, h, i etc. are never needed.
level or shell
number of subshells
type of subshells
n = 1
1
s
n = 2
2
s and p
n = 3
3
s, p, d
n = 4
4
s, p, d, f
n = 5
5
s, p, d, f, g
n = 6
6
s, p, d, f, g, h
n = 7
7
s, p, d, f, g, h, i

Electrons behave like they are small magnets. They act like they are spinning like a top. The direction of the magnetic field generated by the "spinning " electron is limited to two extremes. The "UP" and the "DOWN" conditions. The electron spin can be cancelled when two electrons of opposite spin are in the same orbital as happens in helium, He 1s2. The helium atom shows no magnetic properties. Atoms with an odd number of electrons like lithium, Li 1s2 2s1 are paramagnetic.
Atoms and ions with unpaired electrons are "paramagnetic". They exert a magnetic field. Atoms with many unpaired electrons exert a stronger magnetic field. These observable properties are one piece of evidence for our model of electron configurations. In metals like iron the unpaired electrons act in concert and form "domains" with an increased magnetic character. This is called ferromagnetism.
Free radicals are particles that have an unpaired electron. Their existence is detected by checking for magnetic fields. The radicals are reactive and are believed to play a role in aging and initiation of cancer. Antioxidants are molecules that react with free radicals and remove them. This keeps them from reacting with normal molecules in the body.
electron spin produces magnetism

A beam of rays came out from the cathode and hit the anode is called cathode..

The beam was composed of negatively charged fast-moving particles.

•Most of the mass of the atom was carried by the electrons (>1000 e-)
• An atom was a positively charged sphere with low density
•Negatively charged electrons embedded in it like a ‘plum pudding’

determine the conc.

During today's chem lesson, Miss Jee asked us to think about how to determine the concentration of the solution.

a. Students will create a standard curve, plotting the relationship between the concentration of a solution and the amount of light that it is able to absorb. [Content Standard Unifying Concepts- Change, constancy, and measurement] [9-12 Content Standard B- Properties of matter]
b. Students will be able to use the standard curve they have created to determine the concentration of an unknown solution. [9-12 Content Standard A- Formulate explanations using evidence]

Materials:
CBL System
TI Graphing Calculator [9-12 Content Standard E- Understandings about science and technology]
Vernier Colorimeter
Vernier adapter cable
TI-Graph Link
One cuvette
Five 20 x 150 mm test tubes
Tissues (preferrably lint free)
30 mL of 0.40 M NiSO4
5 mL of NiSO4 of unknown concentration
two 10 ml pipets (or graduated cylinders)
pipet pump or pipet bulb
distilled water
test tube rack
two 100mL beakers
stirring rod [Teaching Standard D- Make accessible science tools]

Procedure:
1. Using the table below, use the distilled water provided to dilute the NiSO4 and make 5 solutions with known concentrations.

Trial Number
0.40 M NiSO4
(mL)
H20
(mL)
Concentration
(M)
1
2
8
0.08
2
4
6
0.16
3
6
4
0.24
4
8
2
0.32
5
10
0
0.40
2. Calibrate the colorimeter. Prepare a blank by filling a cuvette ¾ full of distilled water. With the light source turned off, enter this absorbance value obtained as 0% transmittance. With the wavelength knob in the Red LED position (635 nm), enter the absorbance value obtained as 100% transmittance.

3. In this same manner, collect absorbance data for each of the five standard solutions. When the percent transmittance value for each solution is displayed , enter the molar concentration for that solution.

4. Using your calculator, construct a graph of absorbance vs. concentration. Then perform a linear regression on your data. [9-12 Content Standard A- Use mathematics to improve scientific communication] If the data you have obtained are consistent with Beer’s Law (a direct relationship between absorbance and concentration), the regression line should closely fit the five data points and should pass through (or near) the origin of the graph.

5. Obtain about 5 mL of the unknown solution of NiSO4 . Find the absorbance for the unknown solution. Then use your calculator to interpolate along the regression line on your Beer’s Law curve.

6. Use the TI Graph link cable and program to transfer the graph of absorbance vs. concentration (including the interpolated unknown concentration) to a laptop computer. Print a copy of the graph.

career

Mm.. Thank you for the comments and i would like the fully explain what this career is about after i interview a shipping broker:)

First of all, a shipping broker doesn't need to swim or even go anywhere near the sea. Being a broker, all i have to do is to use the computer and exchange information of the shipping industry, for example, which buyer is interested and which ship is available to carry the goods.. Then, shipping brokers can help different parties to cooperate. Basically, communication is very important so shipping brokers normally need to talk a lot on the phone and use msn a lot. In addition, networking for them is also very important. The other reason I like this job is that you get to travel to different places to meet the clients around the world and you can also have high-class because you need to accompany the clients. Because they need to work with clients world-wide, they don’t get to sleep a lot and that’s the part I don’t like about this job.

You might like to ask yourself the following questions:

1) What are some of my strengths?

Maybe is my communication ability because I can easily talk with strangers and I like to talk on the phone a lot.

2) What are some of my weaknesses?

I really need to sleep on time.

3) What are the opportunities available in the short term / long term?

I don’t quite understand the question..

4) How about threats or potential problems that you foresee in this job/industry?

I don’t think there is any because the world is more globalize and there is a great need of transportation of goods.

Yes ! I want to be a shipping broker. I cannot say i LOVE this career but i think i know 80% of this career. Basically because a lot of my family members are working in that industry and i kinda think it is cool to be a broker. Of course i have dreamt of becoming a model, journalist, DJ and even artist. Maybe because these jobs look cool and their job seems a lot easier. Realistically, i know nothing about the job. I mean it is hard to know a job by just research about it right? So, that's why i choose broker for the moment.





And here is some research i that did...

Shipbroking is an activity which forms part of the international shipping industry. Shipbrokers are specialist intermediaries between shipowners and the charterers who use ships to transport cargo, or between buyers and sellers of ships.
Larger Broking firms have separate departments specialising in Dry Cargo Chartering, Tanker Chartering, Containers, Sale & Purchase and sometimes also Demolition sales and Research. Major shipbroking centres include London, Oslo, Piraeus, New York, Houston, Hamburg, Copenhagen, Singapore, Tokyo, Hong Kong and Shanghai. Although some brokers cover more than one discipline, most shipbroking activity can be divided as follows:
Contents[hide]
1 Sale and Purchase
2 Dry Cargo Broking
3 Tanker Broking
4 Container Broking
5 References
6 External links
//

[edit] Sale and Purchase
S&P brokers handle the buying and selling of existing or new ships (called newbuildings in industry parlance). S&P brokers discuss opportunities and market trends with shipowners, report on sales, value vessels, calculate freight earnings, advise on finance and try to find ships for specific employment opportunities. When a ship is sold, brokers usually negotiate on behalf of the buyer and seller on price and terms and also provide a route to resolving any disputes which might arise. Some S&P brokers specialise in the sale of ships for scrapping, which requires a different set of skills.

[edit] Dry Cargo Broking
Dry cargo brokers are typically specialists in the chartering of bulk carriers, and are appointed to act either for a ship owner looking for employment for a ship, or a charterer with a cargo to be shipped. Dry brokers typically maintain large databases of vessel positions, cargoes and rates and pay close attention to the direction of the markets so that they can advise their clients accurately on how to maximise profits or minimise expenses. This area of business is often sub-divided into size classes of bulkers - capesize, panamax and handysize are the main sectors. Each sector involves different cargoes, trade routes, owners and charterers and dry brokers tend to specialise in one of these sectors.

[edit] Tanker Broking
Tanker brokers specialise in the chartering of tankers, which requires an entirely different set of skills and knowledge to dry cargo broking. Tanker brokers may specialise in crude oil, gas, oil products or chemical tankers.
Tanker brokers negotiate maritime contracts which are known as Charter Parties. The main terms of negotiation are freight/hire and demurrage.
Freight or Hire rate (when a time charter) for crude oil tankers is based on universal calculations assessed once a year know as worldscale. For specialist ships, such as LNG tankers, where the charter market is smaller, prices are agreed at a fixed rate between the parties.

[edit] Container Broking
Container brokers specialise in the chartering of container ships and provide container ship owners and charterers with market-related information.
Brokers
If you're looking on the Internet for a car shipper, the companies you see will most likely be brokers, like National Car Shipping. Brokers have access to hundreds of transporters and can generally accommodate you on any location you may need service to or from. They can also assist you with paperwork required in transporting a vehicle and can use their experience to guide you through the process. Brokers also are required to keep insurance and authority records of the transporters they use on file. They usually cannot, however, give you an exact loading schedule for your vehicle at the time you book your vehicle shipment order. Since they do not own the trucks they cannot dictate what routes they run. They can provide you with estimated times for loading and delivery but until they know which transporter will be moving your car they won't be able to give exact dates. Since they move a lot of vehicles and can choose the best transporter for the route you need they can potentially offer lower rates. Brokers all have their own terms and conditions so be sure and read them carefully. (Here are ours.)
Both brokers and transporters are required to have federal authority to move vehicles across state lines. Transporters have minimum levels of insurance they must carry and brokers must carry a $10,000 bond. You can check the federal status of any carrier or broker at the Department of Transportation.

my weakness and strength!!

Basically my weakness is memorising work in chemistry. For example last time i failed to memorise the oxidising agents and reducing agents, solubility of salts. I understand that these facts are very important when i do chem questions but i can cope with it if i pratice enough.

My strength in chem is calculation and problem solving. I used to score for the calculation, balance equation and it becomes easy after only a few pratices. In addition, i tend to solve problems and no matter it is right or wrong i like to just fill the page. Most of the time, i got the answers if i try hard enough.

In the notes Atoms, Moles and Stoichiometry, I 've learnt..
1.the different between basic units and derived units
2. how to determine the number of significant figures in a number
3.proceed via mole ratio in the balanced equation