Theory Flashcards
How is estimating the size of an atom complicated? How to approach it then? Explain via examples?
The size of an atom is 1.2 X 10⁻¹⁰ m in radius which is veeeery small. Secondly, the electron cloud of an atom doesn’t have sharply demarcated boundaries, so determination of atomic size cannot be precise. So we don’t really have any practical method by which atomic size can be measured.
a). Covalent radius
But we can make an estimate of the size of an atom of a NON-METALLIC element by measuring the distance between two atoms when they are bound together by a single bond in a covalent molecule and from the value, the covalent radius of the element can be calculated.
Eg. Cl₂ : 198pm Cl atomic radius: 99pm
b) metallic radius
Half the internuclear distance separating metal cores in metallic crystal.
Eg. Distance between 2 adjacent copper atoms in solid copper atom is 256pm. Metallic radius: 128pm
Atomic radii can be measured by?
X-Ray or other spectroscopic methods
