Final answer:
Strontium is the element that is most like calcium in terms of physical and chemical properties because they both belong to Group 2, the Alkaline Earth Metals, and share similar reactivity and compound formation characteristics.
Step-by-step explanation:
The element that is most like calcium in terms of physical and chemical properties is strontium (Sr). Both calcium and strontium are part of the Alkaline Earth Metals group in the periodic table, which is Group 2. These elements are shiny, somewhat reactive metals that are good conductors of heat and electricity. As Group 2 elements, they also form compounds with oxygen in a one-to-one ratio, oppose to the Group 1 elements that form compounds with a two-to-one ratio. Additionally, calcium and strontium, as well as other alkaline earth metals, react with water to form hydrogen and metal hydroxides, and form salts many of which are insoluble in water due to high lattice energies.