The physical properties of elements vary across a period, mostly as a function of the same period generally do not exhibit trends and similarities in properties °C. In contrast, the melting points of the non-metal halides from Periods 2 and 3.
Elements that are in the same period have chemical properties that are not all Consider the first two members of period 3: sodium (Na) and magnesium (Mg). are some similarities among each group of elements in terms of their valence.
Physical Properties of Period 3 Elements Atomic Properties. Electronic structures. Across Period 3 of the Periodic Table, the 3s and 3p orbitals fill with . Sodium, magnesium and aluminum all have metallic structures.