In the Modern Periodic Table, calcium (atomic number 20) is surrounded by elements with atomic number 12, 19, 21 and 38. Which of these have physical and chemical properties resembling calcium?

[Extra information: 

Periodic table: A periodic table is a tabular display of all the chemical elements that are arranged by the order of their atomic number, electronic configuration, and recurring chemical properties. 

It displays the names, atomic numbers, symbols and atomic weights of known elements. It serves as a great tool for solving chemistry problems.

A periodic table is divided into groups (columns), where elements with each group behave similarly while bonding with other elements; and periods (rows), where elements in one period have the same number of electron shells.

The periodic table is important because it is organized to provide a great deal of information about elements and how they relate to one another in one reference. The table can be used to predict the properties of all the elements, even those that have not yet been discovered.]