Combining Capacity or Valency of Elements
Combining Capacity or Valency of Elements
Combining capacity or Valency :
We know that the outer most shell of an atom is known as valence shell. The electrons in this outer most shell is known as valence electron. The outer most shell of an atom can accomodate maximum of eight electrons known as complete octet.
As we know that elements with complete octet are non reactive and are stable . Eg: Noble gases. Elements other than group 18 (noble gases) contain less than 8 electrons in there outer most shell.These atoms are reactive and unstable.To get stability they need to aquire the nearest noble gas configuration with the help of different reactions. During these reactions atoms either gain or lose electrons.The number of electrons lost, gained or shared by an atom determines the valency of the elements concerned. The elements those lose electrons are called as cations and elements those gain electrons are called as anions .
Valency of elements having 1-4 electrons in their outermost shells are determined by the following rule:
Valency = Number of electrons in the outermost shell
For example:
Valency = 8 - numbers of electron inthe outermost shell
For example:
Aluminium contains __________ electrons in its outermost shell and its valency is also _________. | |||
| Right Option : D | |||
| View Explanation | |||
Hydrogen(H), Lithium(Li), and Sodium(Na) have ___________ electron in their outer most shells. | |||
| Right Option : B | |||
| View Explanation | |||
The atomic numbers of three elements A, B and C are 10, 18 and 8 respectively. Identify the element which is chemically reactive? | |||
| Right Option : C | |||
| View Explanation | |||
Students / Parents Reviews [20]
Abhyas is an institute of high repute. Yogansh has taken admission last year. It creates abilities in child to prepare for competitive exams. Students are motivated by living prizes on basis of performance in Abhyas exams. He is satisfied with institute.
Yogansh Nyasi
7thWe started with lot of hope that Abhyas will help in better understnding of complex topics of highers classes. we are not disappointed with the progress our child has made after attending Abhyas. Though need to mention that we expected a lot more. On a scale of 1-10, we would give may be 7.
Manya
8thThird consective year,my ward is in Abhyas with nice experience of admin and transport support.Educational standard of the institute recumbent at satisfactory level. One thing would live to bring in notice that last year study books was distributed after half of the session was over,though study ...
Ayan Ghosh
8thWhen I have not joined Abhyas Academy, my skills of solving maths problems were not clear. But, after joining it, my skills have been developed and my concepts of science and SST are very well. I also came to know about other subjects such as vedic maths and reasoning.
Sharandeep Singh
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Shreya Shrivastava
8thA marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
Archit Segal
7thAbout Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
Shreya Shrivastava
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Upmanyu Sharma
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Yatharthi Sharma
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Shivam Rana
7thUsually we see institutes offering objective based learning which usually causes a lag behind in subjective examinations which is the pattern followed by schools. I think it is really a work of planning to make us students grab the advantages of modes of examination, Objective Subjective and Onli...
Anika Saxena
8thIt was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.
Cheshta
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Ayan Ghosh
8thThe experience was nice. I studied here for three years and saw a tremendous change in myself. I started liking subjects like English and SST which earlier I ran from. Extra knowledge gave me confidence to overcome competitive exams. One of the best institutes for secondary education.
Aman Kumar Shrivastava
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Eshan Arora
8thMy experience with Abhyas academy is very nice or it can be said wonderful. I have been studying here from seven class. I have been completing my journey of three years. I am tinking that I should join Abhyas Academy in tenth class as I am seeing much improvement in Maths and English
Hridey Preet
9thIn terms of methodology I want to say that institute provides expert guidence and results oriented monitering supplements by requsite study material along with regular tests which help the students to improve their education skills.The techniques of providing education helps the students to asses...
Aman Kumar Shrivastava
10thIt has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
Barkha Arora
10thAbhyas academy is great place to learn. I have learnt a lot here they have finished my fear of not answering.It has created a habit of self studying in me.The teachers here are very supportive and helpful. Earlier my maths and science was good but now it has been much better than before.
Barkha Arora
10thBeing a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
