Green Chemistry
In seeking a cleaner and convenient environment and a more sustainable future, chemists developed a set of principles which is called the Green Chemistry. This was published by Paul Anastas and John Warner in Green Chemistry: Theory and Practice, New York: Oxford University Press in the year 1998.

12 Principles of Green Chemistry:

1. Prevention: It is better to prevent waste than to treat or clean up waste after it has been created.

Example: It is better to prevent throwing our trash anywhere than cleaning it so that when we clean, we wouldn't clean the same amount as what we've cleaned before since we have prevented the increase of the trash around us. 
2. Atom Economy: Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product.

Example: When you make paper out of leaves, it follows this principle because you're using non harmful things to make paper.
3. Less Hazardous Chemical Synthesis: Wherever practicable, synthetic methods should be designed to use and generate substances that possess little or no toxicity to human health and the environment.

Example: Using palm oil as a replacement for fuel because it's non-hazardous.
4. Designing Safer Chemicals: Chemical products should be designed to effect their desired function while minimizing their toxicity.

Example: In producing skin products, we can use natural products rather than using organic or synthetic products.






5. Safer Solvents and Auxiliaries: The use of auxiliary substances (e.g., solvents, separation agents, etc.) should be made unnecessary wherever possible and innocuous when used.

Example: Using salt and/or water as solvents or separation agents.





6. Design for Energy Efficiency: Energy requirements of chemical processes should be recognized for their environmental and economic impacts and should be minimized. If possible, synthetic methods should be conducted at ambient temperature and pressure.

Example: Chemical processes that needs or requires the use of energy should be minimized if possible. Instead of using electricity to heat a chemical like the hot plate, we can just use the tirril burner or alcohol lamp in heating.





7. Use of Renewable Feedstocks: A raw material or feedstock should be renewable rather than depleting whenever technically and economically practicable.

Example: Styrofoam is an example of a non-renewable feedstock or material. It violates this principle because once it is destroyed, we cannot use it anymore and the only way to get rid of it is depleting or diminishing its number or quantity that removes the essence of this principle.



8. Reduce Derivatives: Unnecessary derivatization (use of blocking groups, protection/ deprotection, temporary modification of physical/chemical processes) should be minimized or avoided if possible, because such steps require additional reagents and can generate waste.



9. Catalysis: Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.



10. Design for Degradation: Chemical products should be designed so that at the end of their function they break down into innocuous degradation products and do not persist in the environment.



11. Real-time analysis for Pollution Prevention: Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior to the formation of hazardous substances.



12. Inherently Safer Chemistry for Accident Prevention:
Substances and the form of a substance used in a chemical process should be chosen to minimize the potential for chemical accidents, including releases, explosions, and fires.







References:
http://www.epa.gov/gcc/pubs/principles.html
http://en.wikipedia.org/wiki/Green_chemistry
http://academic.scranton.edu/faculty/cannm1/intro.html



Made by:
Admin, Christelle Jayco. 
Thank you Gaby Fernandez & Kyra Yu for helping me!!!

SIGNIFICANT DIGITS AND SCIENTIFIC NOTATION

SIGNIFICANT DIGITS (also known as scientific figures)

Significant digits are connected to rounding. We use this so that we know what the significant digits are. What really are the important digits in a group of numbers. Here you will also findout when the zeros will be considered significant and not how it will happen. 

   

RULES FOR SIGNIFICANT DIGITS:

1. ALL none zero numbers are ALWAYS significant.

ex. 1,2,3,4,5,6,7,8,9

2. ALL zeros between non-zero numbers are ALWAYS significant.

ex. 5160003487347000006

3. ALL zeros before the 1st non-zero digit are non significant.

ex. 0.00463

4. ALL zeros after the last non-zero digit MAY OR MAY NOT BE significant.

ex. 341.20 and 100

5. ALL zeros at the right of the decimal point and at the end of the number are always significant

ex. 0000000000000000000.98045 and 0.00000000000000000000

6. ALL zeros which are to the left of a written decimal point and are in number greater than or equal to 10 are ALWAYS significant.

ex. 10.0

EXERCISES!!!: (on a 1/8 sheet of paper, state on every blank how many significant digits there are in each number) 

__________ 1) 45,000,000,000,000

__________ 2)100,708,300.000 

__________ 3)000002.048000000000

__________ 4)9.00

__________ 5)23,000,000,000.000000

So now we will move on and we will tell you about

SCIENTIFIC NOTATION

Scientific Notation simply makes answers shorter and faster to write. There will be less numbers.  

A number is in Scientific Notation if it has been expressed in the form: a x 10 raised to the power b where 1 < = a > 10 and b is an integer. The following table presents examples and how they may be expressed in scientific notation. 

     Numbers                                           Scientific Notation     

                   123                                          1.23 x 10 raised to the power of 2

                         0.0234                                     2.34 x 10 raised to the power of -2    

                       1230000                                  1.23 x 10 raised to the power of 6     

                   0.000321                                  3.21 x 10 raised to the power of -4

Here for example you have 123 and you have to transform it into scientific notation. You have to get the first significant digit which is 1 and move the decimal 2 places to the left so you can come up with the answer that you can see in the table above. 10 is always the base. The sign of the exponent depends on where you are moving the decimal point. If you are moving the decimal to the right then it becomes negative. To the left it becomes positive.

EXERCISES!!!! ( Try solving these on a 1/4 sheet of paper)

_______________ 1) 300

_______________ 2) 4,000

_______________ 3) 5,720,000,000

_______________ 4) 0.0000000006

_______________ 5) 703,421,000,000,000.000

_______________ 6) 000.000000000000858

_______________ 7) 000.000708

_______________ 8) 143,000,000.000

MEMBERS:

YU

ZULETA

VILLEGAS

VITANZO

VILLA IGNACIO

Box Configuration
- ways in which electrons are arranged around the nuclei of atoms


1. Aufbau Principle

It is a principle in which an atom is “built up” by adding together electrons. This is used to know the electron configuration of an atom, molecule or ion. Electrons fill orbitals beginning at the lowest free possible energy states before filling higher states.

It is also known as "constructing a building". It starts from the lowest to the highest energy level. It follows the ruling or order of the Mnemonic device.

Mnemonics
The Mnemonic device is composed of the s, p, d and f.

• S stands for Sharp (sphere) which contains a maximum of 2 electrons. 
• P stands for Principal (clover) which contains a maximum of 6 electrons.
• D stands for Diffused (dumbbell) which contains a maximum of 10 electrons.
• F stands for Fundamental (undefined) which contains a maximum of 14 electrons.

principle quantum number	number of subshells	the subshell labels
1	1	s
2	2	s,p
3	3	s,p,d
4	4	s,p,d,f

2. Pauli's Exclusion

It is a principle that states that no 2 electrons could possibly have the same 4 quantum numbers. If n, l, and m¹ are identical, m² must be different thus having opposite spins. It also states that an atomic orbital may describe at most two electrons.

Quantum Numbers

This is where the Quantum Numbers enter. Quantum Numbers are numbers that represent on how you will find a certain electron.


Nitrogen - 1s² 2s² 2p³






1. n

• N represents the principle quantum number. It is the last number found in the electron configuration. 
• In the given element, n will be 2 because the last number found in the electron configuration is 2, from 2p³.

2. l

• L represents the azimuthal quantum number. It is used to determine in which orbital the given electron is placed. 
• The equivalents of each Mnemonic are the following: s = 0, p = 1, d = 2, & f = 3.
• In the given element, l will be 1 because the last letter found in the electron configuration is p and p is represented by the number 1.

3. m¹

• M¹ represents the magnetic quantum number. It enables us to determine at what box the given electron is located.

• In the figure above, you can see the different numbers representing each box per each orbital. S only has one box which gives a number represented by 0. P can either be -1, 0, or 1, depending on the given electron. D can range from -2 to +2 and f can range from -3 to +3. 
• In the given element, m1 will be 1 because the 3rd arrow is placed in the 3rd box which is represented by the number 1.

4. m²

• M² represents the magnetic spin of the electron. It can either be + 1/2 or - 1/2. +1/2 is determined by a positive electron or an electron having a clockwise spin of direction. It is represented by an arrow pointing upwards. On the other hand, -1/2 is determined by a negative electron having a counter clockwise spin of direction. It is represented by an arrow pointing downwards.
• In the given element, m² will be +1/2 because the last arrow placed in the boxes is pointing up.

Box Configuration

It is a system used to determine the place of the electrons. It is an electronic configuration described by box notation form i.e., putting an arrow for single electron in a box or a pair of arrows for two electrons in a box. The direction of the arrows gives the orientation of its spin.


Examples:


3. Hund's Rule

Every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin. In short, when electrons occupy orbitals of equal energy, one electron enters each orbital until all orbitals contain one electron with parallel spins.


They occupy each room first with 1 positive spin that should fill up all the boxes in one orbital and once they are completed, that's the time when the negative spins will go with the positive spins.

1s	2s		2p

Exercises:

Provide the electron configurations and illustrate the box notations of the following elements. Give their quantum numbers:

1. Scandium



2. Boron



3. Gallium



4.Strontium



5.Technetium


Group 7 Members:

• Carol Encarnacion
• Kaira Evangelista
• Gaby Fernandez
• Bianca Isaac
• Christelle Jayco

References:

• http://facweb.eths.k12.il.us/chemphys/Word/Chem-Phys%20Electron%20Configuration%20-%20Student.htm
• http://www.iun.edu/~cpanhd/C101webnotes/modern-atomic-theory/aufbau-principle.html
• http://www.asdk12.org/staff/herda_shannon/pages/content/chemistryhs/modernatomictheorynotes.htm
• https://chemistry.twu.edu/tutorial/AufbauSum.html

ELECTRON DISTURBUTION MNEMONICS

HOW ARE ELECTRONS ARRANGED?

Electrons tend to arrange themselves around the nuclei so that they will have the lowest possible energy. They would all like to get into the lowest energy level, sometimes called the K-shell, but are prevented from doing, so by some rules that pop up in quantum mechanics. You can see how electrons are arranged in a particular atom by taking a look at the Periodic Table of Elements. There will always be one electron for each proton, they are positioned in layers called shells.

WHAT? WHAT? WHAT? 

orbitals: pathway of electrons. And where it could be found.
Shells: can only contain a fixed no. Of electrons each shell is associared with a particular range of electron energy and thus each shell must fill completely before electrons can be added to an outer shell.
Energy levels: determines the capacity or no. Of electrons each shell could contain

                                                           

                                                          N= Energy Level

Formula to determine the energy level of electrons

N=2

N=3

                                    2n²

    1st  energy level = 2x1²=2

N=1

            2^nd energy level = 2x2²=8

            3^rd energy level = 2x3²=18

            4^th energy level = 2x4²=32

·         Valence electrons found in the outmost shell

            5^th energy level = 2x5²=50

            6^th energy level = 2x6²=72

32

18

8

2

                                                                     

LET'S TRY SOME EXERCISES! 

Give the electron configuration of the ff:
Ex:
1. Li
Protons:3
Atomic Mass: 7
Neutrons: 4
Electron Configuration: 1s², 2s1


1. Calcium
Protons
Atomic Mass:
Neutrons:
Electron Configuration:

2. Manganese
Protons
Atomic mass:
Neutrons:
Electrons Configuration:

3. Zn
Protons:
Atomic Mass:
Neutrons:
Electron Configurations:

4. Sb
Protons:
Atomic Mass:
Neutrons:
Electron Configuration:

5. I
Protons:
Atomic Mass:
Neutrons:
Electron configuration:

MEMBERS: 

RACADIO

RAMIENTO

RARIZA

REYES

RIMANDO

 

Accuracy and Sensitivity of Measuring Devices

x

x

What is Accuracy and Precision?


Accuracy:  is the degree of closeness of measurements of a quantity to its actual (true) value

Precision: also called reproducibility or repeatability, is the degree to which repeated measurements under unchanged conditions show the same results.

Did You Know?..

• That a  measurement system can be accurate but not precise, precise but not accurate, neither, or both.

How to compute for the Percentage Error?


Percentage Error= (estimated amount - actual amount) / actual amount * 100 


Exercises 

1. In the candy store you estimated that you bough and placed 90 pieces of candy in a jar but there were actually 130 your jar.  Compute for the percentage error.
   
   
   Answer:
   % Error = (90-130)/130 * 100
   = -40/130 * 100
   = -0.308*100 = -30.8% 
2. In the pet store you estimated that there are 7 fishes in an aquarium, but the store owner told you that there were actually 23. Compute for the percentage error.
   
   
   Answer:
   % Error = (7-23)/23 * 100
   = -16/23 * 100
   = -0.696 * 100
         = -69.9 %
   
   
   
   
3. In the classroom, you estimated that there were 27 ballpens that were found but when but then there were only 19 ballpens that were found. Find the percentage error.
   
   
   Answer:
   % Error = (27-19)/19 * 100
   =6/19 * 100
   = 0.316 * 100
   = 31.6 %  
   
   
   
   

By: 

Mikaela Monsalud

Bianca Pagkalinawan

Mikhaela Ponce

Coleen Pacunayen

Mikee Mendoza 

2-5

Quantum Numbers

Quantum Numbers

In solving quantum numbers we always should always use specific representations for determining the quantum numbers of an electron. These specific representations are n, l, ml, ms.

Principal quantum numbers

•  Represented by “n”.
• You can identify it by looking at the energy level or shell where the last electron of a specific element is located.

For example: 2p⁶, the principal quantum number is 2 because 2p⁶ is located at the 2^nd shell.

Azimuthal Quantum number

• represented by “l”.
• You can identify it by looking at the subshell. Subshells are the s, p, d and f from the electron configuration.

The subshells have different kinds of shapes.

S is a sphere shaped area, 

P is a dumbbell shaped area, 

D is a clover shaped area, and 

F is a fundamental shaped area. 

• We also have representations for subshells s, p, d and f when looking for the azimuthal quantum number.

s= 0

p= 1

d= 2

f= 3

For example: 2p⁶, its subshell is p and therefore its azimuthal quantum number is 1.

The magnetic quantum number

• Represented by “ml”.
• It is somehow connected with the azimuthal quantum number.
• You can identify it by looking at the compartment of the element. Every subshell has different numbers of compartments.

                      S= 1 compartment,

                      P= 3 compartments  

                      D= 5 compartments

                     F=  7 compartments

• The center of the compartment is always zero, so if you’re going to look at the left side it means that it is negative and if you are going to look at the right side it means that it is positive.

For example: 2p⁶, its magnetic quantum number is 1 because the 6^th electron of 2p⁶ is located at the 3^rd compartment.

Magnetic Spin

•  The representation for magnetic spin is “ms”.
• Inside of every compartment, there are 2 arrows but their direction is opposite:

               

1.  Upwards which means that arrow is going to a clockwise direction and it denotes +1/2 or having a positive spin.
2. Downwards which means that arrow is going to a counter clockwise direction and it denotes -1/2 or having a negative spin.

• These 2 spins are called magnetic spins

Example for this quantum number: 2p⁶, the magnetic spin of it is -1/2 because the last arrow is going to a counter clockwise direction.