Define:
Atomic size

Define an atom.

(a) Define the following terms: (i) Valency, (ii) Atomic size (b) How do the valency and the atomic size of the element vary while going from left to right along a period in the modern periodic table?

Assertion:The atomic size generally increases across a period and decreases down the group. Reason:Atomic size depends upon valence shell electronic configuration.

Define the atomic mass unit.

What happens to the atomic size of elements on moving from top to bottom of a group.

What is the trend in the atomic size in a group, does it increase or decrease?

Give reasons for Atomic size of an element depends on the nuclear charge of that element.

Assertion : Bond dissociation energy of B-F bond in BF_(3) molecule is lower than C-F bond in CF_(4) molecule. Reason : Atomic size of B-atom is larger than that of C-atom.

Assertion : Bond dissociation energy of B-F bond in BF_(3) molecule is lower than C-F bond in CF_(4) molecule. Reason : Atomic size of B-atom is larger than that of C-atom.

Assertion: Halides of Be dissolve in organic solvents Reason: Atomic size of Be is smaller in the s-block elements.