Scandium has three valence electrons.
To explain this, we need to look at the position of scandium in the periodic table. Scandium is located in group 3 (or IIIA) and period 4. The group number generally indicates the number of valence electrons for the elements in that group. Since scandium is in group 3, it possesses three electrons in its outermost shell (the 3s and 3p subshells). These valence electrons are important because they play a key role in chemical bonding and reactions. In summary, scandium’s three valence electrons are responsible for its chemical properties, allowing it to form various compounds with different elements.