Answer: Argon
Explanation:-
Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom.
The electrons are filled according to Afbau's rule in order of increasing energies and thus the electronic configuration
Total number of electrons = 2+2+6+2+6 = 18
The element which has 18 electrons in its ground state is argon.
Neon has 10 electrons.
Helium has 2 electrons.
Krypton has 36 electrons.
Molarity is defined as the ratio of number of moles to the volume of solution in litres.
The mathematical expression is given as:
Here, molarity is equal to 1.43 M and volume is equal to 785 mL.
Convert mL into L
As, 1 mL = 0.001 L
Thus, volume = = 0.785 L
Rearrange the formula of molarity in terms of number of moles:
n =
= 1.12255 mole
Now, Number of moles =
Molar mass of potassium hydroxide = 56.10 g/mol
1.12255 mole =
mass in g =
= 62.97 g
Hence, mass of = 62.97 g
