Variations in the atomic properties of elements in any period are discussed below. Atomic number: In a period, the elements are arranged in the order of increasing atomic number. The atomic number increases by one unit atomic each element from left to right in a period.
All elements in a group generally show the same valence. From the values given in the above table, the valence of the main group elements is either equal to the number of valence electrons or 8-number of valence electrons.
In liquids, the intermolecular forces are strong enough to keep the particles tied upon to each other but not strong enough to keep them in fixed positions. This is why; liquids can flow and do not have a definite shape.