what valency ?how can we find valency?explain.
a measure of its combining power with other atoms when it forms chemical compounds or molecules.
It's very easy and simple.
1st pt. No. of electrons in last shell should be 8
2Nd Use 2n*n where n is the no. of the shell K,L,M etc. this formula is used to find no. of electrons that can be accommodated in a shell
For ex if you want valency of element with atomic no.34
Then Using the formula
For 1st shell 2*1*1=2
For 2nd shell 2*2*2=8
For 3rd shell 2*3*3=18
Here's the trick adding the electrons in these shells.=28 And the no. left is 6
So as we know we need 8 electrons in last shell so, 2 electrons are less so the valency is -2
if the atomic no.were 36 it would be a noble gas valency=0, 37 then a valency =+1
Valency is a term used in chemistry to describe the combining power or the number of bonds an atom can form with other atoms. It is based on the electron configuration of an element.
To determine the valency of an element, you can follow these steps:
1. Determine the electron configuration: Find the electron configuration of the element you want to determine the valency for. The electron configuration describes the arrangement of electrons in the atom's energy levels.
2. Identify the valence electrons: Valence electrons are the electrons present in the outermost shell (also called the valence shell) of an atom. These electrons are responsible for the atom's chemical behavior and its ability to form bonds.
3. Count the number of valence electrons: Determine how many valence electrons the atom has by looking at its position in the periodic table. The Group number of the element indicates the number of valence electrons. For example, elements in Group 1 have 1 valence electron, while elements in Group 17 have 7 valence electrons.
4. Determine the valency: The valency of an element is based on the number of electrons an atom needs to gain, lose, or share to achieve a stable electron configuration. The valency can be positive if an atom loses electrons or negative if it gains electrons to complete its valence shell.
Here are a few examples to illustrate:
- Sodium (Na) is in Group 1 and has 1 valence electron. It tends to lose this electron to achieve stability, making its valency +1.
- Oxygen (O) is in Group 16 and has 6 valence electrons. It needs to gain 2 more electrons to achieve stability, so its valency is -2.
Remember, the concept of valency can be more complex when dealing with transition metals and elements that can exhibit multiple valences. In such cases, the electron configuration and properties of the element play a role in determining the specific valency.