Calcium (Ca) has two valence electrons.
Explanation of Valence Electrons in Calcium
Calcium is in Group 2 of the periodic table, also known as the alkaline earth metals. Elements in Group 2 all share the characteristic of having two valence electrons. These valence electrons reside in the outermost electron shell (the fourth energy level in the case of calcium) and are responsible for calcium's chemical properties and how it interacts with other elements. Because it has two valence electrons, calcium readily loses these two electrons to form a +2 ion (Ca2+) in chemical reactions, allowing it to achieve a stable electron configuration similar to that of a noble gas.
In summary, the number of valence electrons for calcium can be directly determined from its group number on the periodic table.
