Valency is the combining power or capacity of an element, determined by the number of valence electrons it has and how it interacts with other elements to achieve a stable electron configuration. Silicon’s valency is 4, while oxygen’s valency is 2.
Explanation:
Silicon (Si):
Silicon has an atomic number of 14 and an electronic configuration of 2, 8, 4. To achieve a stable octet, it needs to share or lose four electrons. Therefore, silicon’s valency is 4.
Oxygen (O):
Oxygen has an atomic number of 8 and an electronic configuration of 2, 6. To complete its octet, it needs to gain two electrons. Therefore, oxygen’s valency is 2.