In potassium dichromate (K2Cr2O7), chromium has an oxidation state of +6, balancing the overall charge of the compound.
Ammonia (NH3) has a trigonal pyramidal shape due to the lone pair on the nitrogen atom causing repulsion.
Quicklime is the common name for calcium oxide (CaO), widely used in construction and chemical industries.
Iron (Fe) is a transition metal belonging to the d-block elements in the periodic table.
Sodium chloride (NaCl) is held together by ionic bonds, formed between positively charged sodium ions and negatively charged chloride ions.
When zinc reacts with dilute hydrochloric acid, hydrogen gas is evolved due to the reaction: Zn + 2HCl → ZnCl2 + H2.
