Lewis Dot Structure Example - Octet Rule Exception

Lewis dot structures are useful to predict the geometry of a molecule. Sometimes, one of the atoms in the molecule does not follow the octet rule for arranging electron pairs around an atom. This example uses the steps outlined in How to Draw A Lewis Structure to draw a Lewis structure of a molecule where one atom is an exception to the octet rule. Review of Electron Counting The total number of electrons shown in a Lewis structure is the sum of the valence electrons of each atom. Remember: non-valence electrons are not shown. Once the number of valence electrons has been determined, here is the list of steps normally followed to place the dots around the atoms: Connect the atoms by single chemical bonds.The number of electrons to be placed is t-2n, where t is the total number of electrons and n is the number of single bonds. Place these electrons as lone pairs, starting with outer electrons (besides hydrogen) until every outer electrons has 8 electrons. Place lone pairs on most electronegative atoms first.After lone pairs are placed, central atoms may lack an octet. These atoms form a double bond. Move a lone pair to form the second bond.Question:Draw the Lewis structure of the molecule with molecular formula ICl3.Solution:Step 1: Find the total number of valence electrons.Iodine has 7 valence electronsChlorine has 7 valence electronsTotal valence electrons 1 iodine (7) 3 chlorine (3 x 7)Total valence electrons 7 21Total valence electrons 28Step 2: Find the number of electrons needed to make the atoms happyIodine needs 8 valence electronsChlorine needs 8 valence electronsTotal valence electrons to be happy 1 iodine (8) 3 chlorine (3 x 8)Total valence electrons to be happy 8 24Total valence electrons to be happy 32Step 3: Determine the number of bonds in the molecule.number of bonds (Step 2 - Step 1)/2number of bonds (32 - 28)/2number of bonds 4/2number of bonds 2This is how to identify an exception to the octet rule. There are not enough bonds for the number of atoms in molecule. ICl3 should have three bonds to bond the four atoms together. Step 4: Choose a central atom.Halogens are often the outer atoms of a molecule. In this case, all the atoms are halogens. Iodine is the least electronegative of the the two elements. Use iodine as the center atom.Step 5: Draw a skeletal structure.Since we do not have enough bonds to connect all four atoms together, connect the central atom to the other three with three single bonds.Step 6: Place electrons around outside atoms.Complete the octets around the chlorine atoms. Each chlorine should get six electrons to complete their octets.Step 7: Place remaining electrons around the central atom.Place the remaining four electrons around the iodine atom to complete the structure. The completed structure appears at the beginning of the example. Limitations of Lewis Structures Lewis structures first came into use early in the twentieth century when chemical bonding was poorly understood. Electron dot diagrams help illustrate electronic structure of molecules and chemical reactivity. Their use remains popular with chemistry educators introducing the valence-bond model of chemical bonds and they are often used in organic chemistry, where the valence-bond model is largely appropriate. However, in the fields of inorganic chemistry and organometallic chemistry, delocalized molecular orbitals are common and Lewis structures dont accurately predict behavior. While its possible to draw a Lewis structure for a molecule known empirically to contain unpaired electrons, use of such structures leads to errors in estimating bond length, magnetic properties, and aromaticity. Examples of these molecules include molecular oxygen (O2), nitric oxide (NO), and chlorine dioxide (ClO2). While Lewis structures have some value, the reader is advised valence bond theory and molecular orbital theory do a better job describing the behavior of valence shell electrons. Sources Lever, A. B. P. (1972). Lewis Structures and the Octet Rule. An automatic procedure for writing canonical forms. J. Chem. Educ. 49 (12): 819.  doi:10.1021/ed049p819Lewis, G. N. (1916). The Atom and the Molecule. J. Am. Chem. Soc. 38 (4): 762–85. doi:10.1021/ja02261a002Miessler, G.L.; Tarr, D.A. (2003). Inorganic Chemistry (2nd ed.). Pearson Prentice–Hall. ISBN 0-13-035471-6.Zumdahl, S. (2005). Chemical Principles. Houghton-Mifflin. ISBN 0-618-37206-7.

Unit10 1.1 Understand the Expected Pattern of Development...

Unit 10 Understand child and young person development Understand the expected pattern of development for children and young people from birth to 19 years 1.1 Explain the sequence of rate of each aspect of development from birth – 19 years. 0.3 months They take interest and turn their head towards bright coloured lights They recognize bottle or breast Respond when they hear there mothers voice Wriggle and kick with there arms and legs. Social and Emotional Development Begins to develop a social smile Enjoys playing with other people and might get upset when the person stops intereacting with them Expressive and tries to communicate using there face and body†¦show more content†¦ld Social and Emotional Development Enjoys playing with other children for a few minutes or have a couple of close friends they play with They join in with games that involve taking turns Understand that an item or toy belongs to somebody else and that we share Expresses affection by holding hands or hugging Can separate abit more easier from parents Physical Development Throws a ball overhand They understand the concept of riding bikes and can put it into motion Can walk up and down stairs knowing to put one foot per stair step Enjoys climbing such as climbing frames or trees Cognitive Development They can complete puzzles with 3 or 4 pieces They become very imaginative and make up stories Make mechanical toys work without being shown Language Development They can say there name there age and if there a boy or girl Understand the concept of â€Å"on† â€Å"in† and â€Å"under† e.g the chair is under the table 4 Years old Social and Emotional Development Plays role play games where they are the parents Enjoys role play games where they can dress up and play the role of a character or person they are dressed up as Alot more independent and able to do things for themselves Imagines that things they cant see like in dark cupboards or unfamiliar objects might be a monster They cant always make the difference between reality and fantasy like something they see on t.v thats in a cartoon they

How Sports Affect Academics Free Essays

Narator: This Reflective Piece consists of three persons who are John, Rodney and Paul. Narrator: Week before Cape results are out John: So fellas, cape results coming out? Feel allyuh do good? Rodney: I hope so, I put in enough time and study because I was behind and I wanted to prove that I could do what nobody expected of me and excel. Paul: Hahaha, Rodney why you studied? You are still going to fail? Rodney: No, I stopped basketball to study and I made some good sacrifices. We will write a custom essay sample on How Sports Affect Academics or any similar topic only for you Order Now Paul: Stopped basketball? Make me stop football na? I’m going to do excellent in Cape and get a scholarship just for football. John: Well like you, Paul, I continue to play cricket but I was also focusing on my studies and putting in meh extra work. I balanced my academics with my extra-curricular activities. Rodney: Well, we will see which one of the three techniques worked the best. John: Yes we will see, but I pray to God I succeed. Paul: Ok den, we will see how good I’ve done. Narrator: Walking in school to collect their results John: Ok fellas, now today is the big day. Rodney: Yes it is, we will find out what our future is and what our next step in life is. Paul: Who wanna pray? Rodney: Pray na Paul. Paul: Please Lord, let us get the required grades needed to further our education in what we will like to do and be proud in Jesus name, Amen! Rodney: When you serious, you serious boy Paul but why you couldn’t be serious like that for your school work as you were for football or for this prayer? Paul: I was! Allyuh was just getting fooled. John: Let us just go quickly and get our grades please! Narrator: After receiving the Cape Results Rodney: Yesss! Da wa we talkin bout! John: Dun kno, I do rel good dan. Paul: Hmmm, I did ok, could have done better. Rodney: John and Paul how allyuh do? John: I did great, I got four distinctions and there’s even a bigger surprise. Guess? Paul: Wa is da boy? John: Ok, I also geh an open science schol. Rodney: Weyzz, you did beast, I geh four ones and got an additional mathematics schol. Narrator: A moment of silence grew upon the three friends John: Well, Paul wa you geh? Paul: Orr ok uhmm I got three fours and a five. Five is a pass in Cape so at least I pass all my subjects. Narrator: John and Rodney laughed loudly Rodney: I thought you were going to get a scholarship because of football Paul? What causing that? Paul: Well honestly, I think it is because I did not rely focus a whole lot on my school work and did not manage my time the way I should have done. John: Although I did not quit or take a pause in my extra-curricular activity, I worked harder in pursuing my education and striving for excellence and cricket maybe one ah d reason why I geh an Open Schol too. Rodney: I put my sport on a hold for a while until my Cape Exam pass because I was not one of the brightest students so I could not of balance both basketball and academics. In making my decision I studied hard and made quality sacrifices to geh my Maths Schol. Narrator: Making decisions in further education John: So what allyuh going to do to now? Paul: I think I going to S. A. M and settle down because I realize this life thing rel serious. I wa be an accountant. Rodney: I am going UWI and further my studies in maths. I am going to do a Major in Maths and a Minor in Actuarial Science. I wa be an Actuarial Scientist. John: Well, I am going Harvard and further my studies in sciences, mostly Chemistry. I wa be a Chemist. Rodney: We set our life goals deh eno, so we making up we mind to achieve eh and doe slack off. We wuh stay in touch. John: Yes of course and I hope allyuh excel in allyuh education and Paul, focus this time because I know you could do it. Paul: First, I am praying I get into SAM, but if I do, I will take a different approach in my school work and be serious cuz I wa my life run smoothly after and be proud of myself. John: Yea, later deh. I gone. Rodney: Yea I bussin deh too. Paul: Word, we wuh catch up in d long run. Narrator: The three persons excelled at their different goals and be what they wanted to be. One can surely realize that sports has a good and a bad effect on education but it is in yourself to take it serious and prove you can do it in whatever aspect of sports you are doing and career. In concluding this piece I think one should always â€Å"Strive for Excellence†. .mce-content-body .mce-resizehandle.wildfire-hover { background: rgb(0, 0, 0); }; .mce-content-body [contenteditable="false"] [contenteditable="true"].wildfire-hover { outline: rgb(122, 202, 255) solid 2px; }; .mce-content-body img.wp-media.wildfire-hover { background-color: rgb(237, 237, 237); border-color: rgb(114, 119, 124); };a[data-wplink-url-error], a[data-wplink-url-error].wildfire-hover, a[data-wplink-url-error]:focus { outline: rgb(220, 50, 50) dotted 2px; position: relative; }; How to cite How Sports Affect Academics, Papers