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Course: Class 10 Chemistry (India) > Unit 5
Lesson 4: Periodic trends in valency and atomic sizePeriodic trend of valency
Valency first increases and then decreases as we go from left to right in a period but remains the same in a group. Let's see why.
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Created by Ram Prakash. Created by Ram Prakash.
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In question of when find similar element I will choose incorrect option? How to find right option ?(0 votes)
how can atoms complete their valency?(0 votes)
An atom can get a full outermost shell (ie., noble gas configuration) by losing or gaining electrons. One way for atoms to achieve a full outermost shell is to share electrons in their valence shells. In this way, atoms form a covalent bond. In covalent bonds, two atoms move close enough to share some electrons.
Hope it helped! :)(1 vote)
So, what about the valency in the 3rd period?(0 votes)- Valency in the third period also shows the general trend of valency, ie. it increases and then decreases. The trend is listed below:
Valency of Sodium (Na): 1
Valency of Magnesium (Mg): 2
Valency of Aluminium: 3
Valency of Silicon: 4
Valency of Phosphorus: 3
Valency of Sulphur: 2
Valency of Chlorine: 1
Valency of Argon: 0
Hope this answer helps. ;)(2 votes)
how do i work out the valency for the transition elements on the periodic table? (The elements that are not under the 8 main groups)(0 votes)
@ Victor Sam-Ehumadu I suggest you see this video first:
https://www.khanacademy.org/science/chemistry/periodic-table/copy-of-periodic-table-of-elements/v/periodic-table-transition-metals
(Ignore if you have seen)
And then try working out the valency.
Hope this helps
Nolan R.T :)(0 votes)
What are noble gases?with example.(0 votes)- @ Divya
Noble gases are those gases that have their octets filled i.e all their shells are filled. Unlike other elements that react to get their octets filled, Noble gases on the other hand are let's say born with their shells filled 😀😀. Since they don't react much because their shells are filled we call them Inert gases.
Examples: Neon, Argon, Krypton, Radon,Xenon, Oganesson
I recommend you to view videos on Noble Gases a little more
Hope this helps
Nolan R.T :)(1 vote)
Why valency can not exceed 4?(0 votes)
Valency cannot exceed 4 because essentially, valency is how much electrons an atom needs to lose or gain to achieve noble gas electron configuration. For example, Carbon (C) had the electronic configuration 2, 4. 4 more electrons are needed or 4 can be lost. However Nitrogen (N), has 2, 5 as its configuration. In this case, it can either lose 5 electrons (very difficult) or gain 3. Since gaining 3 is easier, 3 is the valency of Nitrogen. This works for other elements as well. Hope this answers your question!(0 votes)