Helium atom has 2 electrons in its valence shell but its valency is not 2, Explain.

Academic Chemistry NCERT Class 9

The helium atom(E.C =1s²) has 2 electrons in its valence shell but its valency is zero as it is a noble gas and does not form a chemical bond, its duplet is complete.

Tutorialspoint

Simply Easy Learning

Updated on: 19-Jan-2023

19 Views

Which noble gas has less than 8 electrons in the valence shell of its atom? What is this number?
Which element has:(a) two shells, both of which are completely filled with electrons? (b) the electronic configuration 2, 8, 2? (c) a total of three shells, with four electrons in its valence shell? (d) a total of two shells, with three electrons in its valence shell? (e) twice as many electrons in its second shell as its first shell?
An element A has 4 valence electrons in its atom whereas element B has only one valence electron in its atom. The compound formed by A and B does not conduct electricity. What is the nature of chemical bond in the compound formed? Give its electron dot structure.
Which of the following elements has twice as many electrons in its second shell as in its first shell?
(a) What are valence electrons? Where are valence electrons situated in an atom?(b) What is the number of valence electrons in the atoms of an element having atomic number 13? Name the valence shell of this atom.
The electrons present in the outermost shell are called(a) valency electrons (b) octate electrons(c) duplet electrons (d) valence electron.
An atom has atomic number 12, what is its valency, and name the element?
The number of valence electrons in a graphite atom is :(a) 2 (b) 4 (c) 3 (d) 5
Name the shell of an atom which can accommodate a maximum of :(a) 2 electrons?(b) 18 electrons?
Write the distribution of electrons in an atom of element whose atomic number is 18. What is special about the outermost electron shell (or valence shell) of the atom of this element?
(a) Define valency of an element. What valency will be shown by an element having atomic number 14?(b) What is the relation between the valency of an element and the number of valence electrons in its atoms? Explain with examples.
The cation of an element has :(a) the same number of electrons as its neutral atom(b) more electrons than a neutral atom(c) less protons than a neutral atom(d) less electrons than a neutral atom
The total number of electrons in a nitrogen atom is 7. Find the number of valence electrons in it.
The helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?
Write the number of valence electrons present in a nitrogen atom (147 N).

Kickstart Your Career

Get certified by completing the course

Get Started

Advertisements