Question

The atom of an element 'x' has 18protons in its nucleus.what will be the number of electrons present in its various energy shells?write its electronic configuration

Answer 1

Answer:

electrons present in various energy shells are 2,8,8 respectively .

Its configuration will be 2,8,8

Explanation:

Number of protons = number of electrons = Atomic number

since an atom has 18 protons , so its atomic number will be 18 and 18 is the atomic number of ' Argon' thereby the element is argon

It has 18 electrons ( reason is mentioned above)

The number of electrons which can be filled in a particular shell is given by the formula 2n^2 .

here 'n'is number of that shell like 1,2,3 or 4

first shell (K) will have 2 electrons as

2*1^2 = 2*1 = 2

second shell ( L) will have 8 electrons

2*2^2 = 2*4 = 8

and so on for different shells and

outer most shell cannot have more than 8 electrons

if an element has 9 electrons .

In its outer most shell....then 1 electron will be shifted into the next shell

keeping this in mind, we can see that argon has 18 electrons so it will

2 electrons in K shell

8 electrons in L shell and

8 electrons in M shell

adding them gives 18

therefore all the electrons are appropriately placed according to the rules

its electronic configuration will be

2,8,8

its outer most shell is completely filled therefore it is a less reactive element

it is a noble gas