Valence Definition in Chemistry

Valence is typically  the number of electrons needed to fill the outermost shell of an atom. Because exceptions exist, the more general definition of valence is the number of electrons with which a given atom generally bonds or number of bonds an atom forms. (Think iron, which may have a valence of 2 or a valence of 3.) The IUPAC formal definition of valence is the maximum number of univalent atoms that may combine with an atom. Usually, the definition is based on the maximum number of either hydrogen atom or chlorine atoms. Note the IUPAC only defines a single valence value (the maximum), while atoms are known to be capable of displaying more than one valence. For example, copper commonly carries a valence of 1 or 2. Example A neutral carbon atom has 6 electrons, with an electron shell configuration of 1s22s22p2. Carbon has a valence of 4 since 4 electrons can be accepted to fill the 2p orbital. Common Valences Atoms of elements in the main group of the periodic table may display a valence between 1 and 7 (since 8 is a complete octet). Group 1 (I) - Usually displays a valence of 1. Example: Na in NaClGroup 2 (II) - Typical valence is 2. Example: Mg in MgCl2Group 13 (III) - Usual valence is 3. Example: Al in AlCl3Group 14 (IV) - Usual valence is 4. Example: C in CO (double bond) or CH4 (single bonds)Group 15 (V) - Usual valences are 3 and 5. Examples are N in NH3 and P in PCl5Group 16 (VI) - Typical valences are 2 and 6. Example: O in H2OGroup 17 (VII) - Usual valences are 1 and 7. Examples: Cl in HCl Valence vs Oxidation State There are two problems with valence. First, the definition is ambiguous. Second, its just a whole number, without a sign to give you an indication of whether an atom will gain an electron or lose its outermost one(s). For example, the valence of both hydrogen and chlorine is 1, yet hydrogen usually loses its electron to become H, while chlorine usually gains an additional electron to become Cl-. The oxidation state is a better indicator of the electronic state of an atom because it has both magnitude and sign. Also, its understood an elements atoms may display different oxidation states depending on the conditions. The sign is positive for electropositive atoms and negative for electronegative atoms. The most common oxidation state of hydrogen is 8. The most common oxidation state for chlorine is -1. Brief History The word valence was described in 1425 from the Latin word valentia, which means strength or capacity. The concept of valence was developed in the second half of the 19th century to explain chemical bonding and molecular structure. The theory of chemical valences was proposed in an 1852 paper by Edward Frankland.

High School Dropout Rate Is A Significant Indicator Of...

Introduction: High school dropout rate is a significant indicator of future success in life. For high school dropouts, it is harder to find jobs and earn as much money as their graduated peers. On the outside looking in, not being able to graduate is usually associated with school performance, socioeconomic status, parents’ education level and/or lack of motivation. Moreover, there are also underlying factors of race and gender and they both affect performance in high school immensely. In order to study dropout rates, focus should be put on the group of students at risk of dropping out. In terms of high school dropout rate, Oakland Technical High School has distinct differences between different races and sexes. Hispanics have lower†¦show more content†¦Literature Review: Sociologists and psychologists have studied and documented high school dropout rate for many decades. Their focus has been put on statistics of different races/ethnicities, age groups and gender as well as underlying factors of why people drop out. Comparing the dropout statistics of different races is a common theme amongst many sociologists’ studies. The extent of their research addresses many significant aspects of high school drop out but fail to shed light on the differences within races between the two genders. In the scholarly paper â€Å"Dropping Out of High School: The Influence of Race, Sex, and Family Background† by Russell W. Rumberger, he analyzes the underlying issues behind why students drop out. There is significance behind studying dropout rate, as students t hat drop out are usually less able than students who graduate high school. Dropouts are more likely to engage in crime, use drugs and/or alcohol, and have earlier marriages. He addresses several issues as to why students drop out as well as differences between why females and males drop out. (Rumberger) Females are more likely to drop out due to marriage and pregnancy while males are more likely to drop out because they do not like school. (Rumberger) This shows immense inequality between the two sexes as men can simply drop out of school because they want to while

John Keats And Bob Dylan Essay Example For Students

John Keats And Bob Dylan Essay Why Judgments Matter, gives many examples of why value judgments are importantin our lives. I feel that value judgments are as equally important and it shouldbe evident why after briefly explaining Friths examples and my own as well. In his first example, Mr. Frith gives insight to David Hares comment, Inthe end, Keats was just better than Bob Dylan. The media, without delay,misjudged the true meaning of Hares statement and transposed it into a debateof value. Although Mr. Frith did not agree with the medias tactics, he didagree with the ?value debate. Mr. Frith Feels that value judgmentsorganize social relations in our life, and he further proves this pointusing an example from popular music. Mr. Frith focuses on views in musicstudies. Judgments about musicians are generally made in two ways. Firstly, isthe elevation of excitement with ?community'(joining of performers and theiraudience). Secondly, aesthetic and ethical sub-tones during community. Thisvalue placed upon the musicians is very important, this is possibly the decidingfactor in the performers career. If more fans come to a concert, then theperformer becomes more popular or valuable. The same goes for the messages sentout by the performer during a per formance. A message that is widely accepted andadorned will attract more fans. I find that the critical analysis of valuejudgments in our lives is of equal importance. I agree with Mr. Frithsfindings and find them to be true in other life settings as well. As individualswe use value judgments to prioritize important characteristics in our life,which shape us into cultural individuals. We place a high judgment on the socialaspect of our culture. Some examples of this include; friendships, personalappearances, and material items. In friendships, we place value judgment onmoral attributes set by others. It is these attributes that we judge to beworthy or unworthy of our friendship. Those of similar moral values tend to findeach other in companionship. In personal appearances, we place value on what werepresent ourselves to be. Higher income families tend to pay more attention tothis value for it is a language in which is unspoken. Financial value of onesappearance and the personal valu e (self esteem) of ones self tend to runparallel. People place different values on the material items they posses. Twofamilies may bring the same income into a household, and posses some of thesimilar materials. However, it is the value they place on their material itemsthat make them different. It is this difference that brings out the subjectiveindividuality. Evaluation is a key cultural activity, according to Frith. Without evaluation we would not be able to set some separation between eachother as individuals, eventually becoming numb to culture as we know it. I feelit is imperative that we evaluate every aspect of our lives, in turn ensuringthe greatest personal happiness. How does one attain a favorite? Not bysuggestion of a higher authority, but by evaluation. Putting value on things andmaking value judgments is what enables us to label what we like and what makesus happy. Without it, we would not be happy.

Malcolm X Persuasive Essay Example For Students

Malcolm X Persuasive Essay The year was 1925, and someone special was born. His birth name was Malcolm Little, however there were big things in store for this child. Born in Omaha, Nebraska. The seventh of eleven children born to Earl Little, an organizer for Marcus Garveys ;quot;back-to-Africa;quot; movement (Comptons encyclopedia online). At age six Malcolms father was murdered. As a result his mother later suffered a nervous breakdown, and the family was separated by welfare agencies (Comptons encyclopedia online). Later in life he would blame these same agencies for destroying his family. He was bounced around from boardinghouses and schools, and dreamed of becoming a lawyer only to be discouraged by his teachers. After leaving school, in the eighth grade, he lived with a relative in Boston, Mass. He shined shoes, worked in a restaurant and on a railroad kitchen crew. In 1942 he moved to a section in New York called Harlem. Where he lived as a hustler, cheating people to make money for himself. He also sold drugs and became a drug addict himself. A rival drug dealer named quot;West Indian Archiequot; ran him out of New York. And he ended up back in Boston. Where he started a burglary ring, which consisted of friend named Shorty, a pretty boy type of fellow named Rudy, a woman that Malcolm dealt with named Sophia and one of her friends (Alex Haley 168). He soon found out that crime does not pay, when he soon got arrested and stolen items were found in his possession. The Negroes of that group was sentenced to eight years, while the whites of the group were sentenced to only two. This put an image in Malcolms head on how the justice system was ran. While in prison. Malcolm was well known to the guards. One time he was asked to state his number, but instead he said he forgot his number. The guards beat him and sent him to the ;quot;darkroom;quot;. In the darkroom he met Brother Bains. Bains was a man everyone respected including guards. He was known as a real man and gave speeches about Islam. Malcolm did not listen at first; however it didnt take him long to listen to the words of black empowerment, spoken by brother Bains. The black Muslims prediction that in the near future a great war would take place in which whites would be destroyed and black people would rule the world through the power of Allah, their creator. To prepare for this Brother Bains preached, the importance of self-restraint, opposed the use of drugs and alcohol, and organized self-help groups. Malcolm Little was converted to this faith. Instead of wasting his time in prison getting into more trouble, he begins to read and broaden his thoughts. As he did this, his mind opens up to knowledge. He also tried to improve in other areas such as appearance and speech. He decided not to associate himself with former friends he got in trouble with, and formed new friendships with people of the same faith. He left prison Malcolm X. An image popped into my head while reading quot;the Autobiography of Malcolm Xquot;(Alex Haley 231). The image of a strong man standing in the middle of stage giving a speech. The year is 1953. At the height of racial tension, the city is Detroit. Malcolm X is giving a speech after a run in with FBI agents concerning the nation of Islams practices, and how their message was being used. He stands on the pulpit, and delivers a message. ;quot;We didnt land on Plymouth rock, my brothers Plymouth Rock landed on us!quot; Its a clear message to his followers. If you want to succeed, first get from under that rock. .u54bd9e09c501f29c4925b492d74645d1 , .u54bd9e09c501f29c4925b492d74645d1 .postImageUrl , .u54bd9e09c501f29c4925b492d74645d1 .centered-text-area { min-height: 80px; position: relative; } .u54bd9e09c501f29c4925b492d74645d1 , .u54bd9e09c501f29c4925b492d74645d1:hover , .u54bd9e09c501f29c4925b492d74645d1:visited , .u54bd9e09c501f29c4925b492d74645d1:active { border:0!important; } .u54bd9e09c501f29c4925b492d74645d1 .clearfix:after { content: ""; display: table; clear: both; } .u54bd9e09c501f29c4925b492d74645d1 { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .u54bd9e09c501f29c4925b492d74645d1:active , .u54bd9e09c501f29c4925b492d74645d1:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .u54bd9e09c501f29c4925b492d74645d1 .centered-text-area { width: 100%; position: relative ; } .u54bd9e09c501f29c4925b492d74645d1 .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .u54bd9e09c501f29c4925b492d74645d1 .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .u54bd9e09c501f29c4925b492d74645d1 .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .u54bd9e09c501f29c4925b492d74645d1:hover .ctaButton { background-color: #34495E!important; } .u54bd9e09c501f29c4925b492d74645d1 .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .u54bd9e09c501f29c4925b492d74645d1 .u54bd9e09c501f29c4925b492d74645d1-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .u54bd9e09c501f29c4925b492d74645d1:after { content: ""; display: block; clear: both; } READ: Of Ambition Essay He insisted that ;quot;black is beautiful,;quot; and that African Americans must take control of their own destiny. As Malcolm was giving a speech at the autobahn in New York City. Three men gunned him down, in cold blood, in front of his wife and children. At the end of Malcolms life. He was a changed man, a man no longer involved with racism although he had a large following he saw an even larger picture. He saw a world where people of all colors and religions could help one another instead of fight one another. His most enduring messages are one of black pride and self-respect, combined with his uncompromising rejection of racism. Bibliography OUTLINE I. Malcolm Little A. The beginning B. Separated from family C. Moving around II. Life of Crime A. Being sentenced to jail B. Introduction to Islam C. Name change to Malcolm X III. Conclusion A. Speech B. His gift

Social Pressure and Change

XYZ Company manufactures agricultural chemicals. A year ago, the company experienced significant scandals including charges of stock fraud, harassment lawsuit against several executives and dumping waste into a neighboring wildlife preserve.Advertising We will write a custom essay sample on Social Pressure and Change specifically for you for only $16.05 $11/page Learn More Why might such Pressure Cause XYZ to Change? The external pressure facing XYZ might make the company to embrace change because the firm has to adhere to societal expectations in regard to environmental responsibility and general community involvement. Recently, information and modern technology have contributed extensively to the growth of social pressure, since information regarding firms that do not conform to social standards spread quickly. Also, external members expect that companies conduct business fairly, maintain favorable working conditions for employees and carry out activit ies that do not harm the environment. Failure to do so may spur demonstrations by community members or warnings by environmental pressure groups, in order to force the company to conduct activities that preserve the environment. Also, XYZ Company may face prosecution in a criminal court, due to stock fraud. Besides, failing to adhere to societal expectation will, ultimately, create an unhealthy reputation for the company, which might make customers obtain products from other firms that have similar products. How does this affect the Organizational Ethics of Work at XYZ? Outside pressure, regarding the above mentioned issues, will affect organizational ethics of work at XYZ. First, management practices must be adjusted to suit the needs of employers. As mentioned, in the introduction, a number of executives have filed harassment lawsuits against the company. This implies that organizational ethics have to be adjusted, in order to enhance worker satisfaction and productivity in the co mpany. Besides, XYZ needs to impact outside members positively, through stopping to dump waste products into the nearby wildlife preserve. This will create a positive public image, which is likely to attract new customers. Lastly, the company has to stop stock fraud, because the public may put pressure on legislators to impose existing regulations regarding stock frauds. The company should ensure that both internal and external auditors receive the right information regarding sales and stocks of the company. What Change might XYZ Incorporate? XYZ needs to establish an ethical workplace through creating, and constantly, improving the code of ethics. This will encourage ethical practices, in the firm, in order to ensure moral conduct and make potential customers and employees consider the company as ethical.Advertising Looking for essay on business economics? Let's see if we can help you! Get your first paper with 15% OFF Learn More The managers, at XYZ, can also create a department entrusted with overseeing ethical practices in the organization. Such a department would denote to all external members that the company has committed to upholding ethical practices. Another change that XYZ may incorporate involves training the entire workforce on new ethical practices that the company desires. Such training programs do not highlight all the practice that must be observed. Rather, the training enables managers to have a framework that they can use to judge whether some actions are ethical or not. Besides, the company should incorporate social goals into the yearly planning processes. Such an approach of meeting social requirements indicates that a company is socially responsible. Lastly, managers at XYZ should be accountable for creating and upholding conditions whereby people are apt to act ethically and reduce situations that promote unethical behavior. Managers, through taking charge of these aspects, can reduce the urge to perform unethical acts, a s well as, promote social responsibility at XYZ. In conclusion, social pressure affects how a company functions. Failure to adhere to such pressure may ruin the reputation of a business, or make a business cease to attract new customers. This essay on Social Pressure and Change was written and submitted by user The Stranger to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here.

Free Essays on Bridge to Terabithia

â€Å"Bridge to Terabithia† The two main characters in the story are Jesse and Lesley who are the protagonists. Jesse is a sixth grade boy trying to make it through the school year without getting beat up by the antagonist, a girl, who is the biggest bully in school. Lesley, on the other hand, is an outgoing girl with a great attitude towards life. The plot of the story is when Jesse and Lesley decide to create a make believe world just for themselves. They call it Terabithia which is the setting of the story. It’s a secret place in the forest that only they know about. Jesse is a great artist and often brings his work to Terabithia for Lesley see. Lesley also brings the dog that Jesse bought for her to Terabithia. They named him Prince so he could be the prince of Terabithia. The foreshadowing of my story is when Jesse comes home to find that the television is off which was extremely unlikely at his house. Then he was told about the climax, which was when Lesley was trying to cross the bridge to Terabithia and she slipped and fell off in the rain. Jesse was at the Art Museum with his teacher when this happened. Jesse goes through many phases of denial. He has flashbacks of all the great times he and Lesley had together. This is a major conflict for Jesse because of how much Lesley meant to him and how she had become his only best friend. The tone of my book has now changed from exciting, fun, and adventurous to sad and very teary. The mood now is very depressing. Jesse starts to have trouble concentrating in school and is depressed all the time. He doesn’t even care if he’s bullied anymore. When he goes to school for the first day or two after the incident, the children were asking lots of questions. The next day there were fewer questions and then they stopped. The irony of this was that Jesse still knew where their special place was, the one that nobody else knew about. J... Free Essays on Bridge to Terabithia Free Essays on Bridge to Terabithia â€Å"Bridge to Terabithia† The two main characters in the story are Jesse and Lesley who are the protagonists. Jesse is a sixth grade boy trying to make it through the school year without getting beat up by the antagonist, a girl, who is the biggest bully in school. Lesley, on the other hand, is an outgoing girl with a great attitude towards life. The plot of the story is when Jesse and Lesley decide to create a make believe world just for themselves. They call it Terabithia which is the setting of the story. It’s a secret place in the forest that only they know about. Jesse is a great artist and often brings his work to Terabithia for Lesley see. Lesley also brings the dog that Jesse bought for her to Terabithia. They named him Prince so he could be the prince of Terabithia. The foreshadowing of my story is when Jesse comes home to find that the television is off which was extremely unlikely at his house. Then he was told about the climax, which was when Lesley was trying to cross the bridge to Terabithia and she slipped and fell off in the rain. Jesse was at the Art Museum with his teacher when this happened. Jesse goes through many phases of denial. He has flashbacks of all the great times he and Lesley had together. This is a major conflict for Jesse because of how much Lesley meant to him and how she had become his only best friend. The tone of my book has now changed from exciting, fun, and adventurous to sad and very teary. The mood now is very depressing. Jesse starts to have trouble concentrating in school and is depressed all the time. He doesn’t even care if he’s bullied anymore. When he goes to school for the first day or two after the incident, the children were asking lots of questions. The next day there were fewer questions and then they stopped. The irony of this was that Jesse still knew where their special place was, the one that nobody else knew about. J...

Analyze white lies Essay Example | Topics and Well Written Essays - 500 words

Analyze white lies - Essay Example Her classmates assume that she Is white, as the classmate does when she holds her hand in an act of unity. she is though sad but optimistic in life. (Trethewey, Natasha) Trethewey has used color imagery in the poem constantly, especially in the first stanza. The poet mentions six colors, which are all different, and all describing the lies. "light-bright, near-white, high-yellow, red-boned, white, and black." It is an African American speaker who could lie frequently, though the lies did not mean anything much. She would lie about where she lived, and where she bought her clothes, "uptown ..home made dresses came out the window of Maison blande,"but would also lie about being African American. She did pass easily for being a white. It's actually really sad the way she describes lying about her skin color. She writes, "I could even keep quiet, quiet as kept, like the time a white girl said "squeezing my hand, Now we have three of us in this class." It is sad because she is lying to be part of the group. She writes "squeezing my hand," brings the sense that she only lied because she was amazed by the way the girl was behaving as a good friend. The fir st stanza does describe her as a light skinned for an African American.