valency increases or decreases in a period??
Answers
Answer:
Valency in the periodic table across a period first increases and then decreases. There is no change going down a group.
However, this periodic trend is sparsely followed for heavier elements (elements with atomic number greater than 20), especially for lanthanide and actinide series.
The greater the number of core electrons, the greater the shielding of electrons from the core charge of the nucleus. For this reason ionization energy is lower for elements lower down in a group, and polarizability of species is higher for elements lower down in a group. The valency does not change going down a group since the bonding behavior is not affected by the core electrons. However, non-bonding interactions such as those just cited are affected by core electrons
Periodic trends are specific patterns in the properties of chemical elements that are revealed in the periodic table of elements. Major periodic trends include electronegativity, ionization energy, electron affinity, atomic radii, ionic radius, metallic character, and chemical reactivity.
Periodic trends arise from the changes in the atomic structure of the chemical elements within their respective periods (horizontal rows) and groups in the periodic table. These laws enable the chemical elements to be organized in the periodic table based on their atomic structures and properties. Due to the periodic trends, the unknown properties of any element can be partially known.
Several exceptions, however, do exist, such as that of ionization energy in group 3, The electron affinity trend of group 17, the density trend of alkali metals aka group 1 elements and so on.
Answer:
Explanation:
Valency in the periodic table across a period first increases and then decreases. There is no change going down a group. However, this periodic trend is sparsely followed for heavier elements (elements with atomic number greater than 20), especially for lanthanide and actinide series.