Practice Exam 4 C/P Section Passage 4 Question 20
Alkaline earth metals are elements found in group IIA that share properties characteristic of metals but form hydroxides when reacted with water and ions with a +2 oxidation state.
The alkaline earth metals include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). Alkaline earth metals have two valence electrons. They are highly reactive and are not found naturally in their elemental state. The two valence electrons are easily removed to form divalent cations. Alkaline earth metals are good conductors of electricity. They are low in ionization energy, low in electron affinity, and low electronegativity. Alkaline earth metals have an oxidation state of +2 and an electronic structure in the S subshell occupied by 2 electrons, denoted as Xs2.
MCAT Official Prep (AAMC)
- Alkaline earth metals have two valence electrons
- They have low ionization energy, low electron affinity, and low electronegativity
- They are highly reactive and often form divalent cations
- They are good conductors of electricity
- Alkaline earth metals have an oxidation state of +2
- Valence electron: an outer shell electron that can participate in chemical bonds
- Ionization energy: the energy required to remove an electron from the valence shell of a gaseous atom
- Electron affinity: the energy change that occurs when an atom gains an electron
- Electronegativity: a measure of the ability of an atom to attract the electrons in a bond
- Oxidation state: a number assigned to an element in chemical combination which represents the number of electrons lost
- Electronic structure: the descriptive numerical assignments to electrons in different energy levels and spin states in an atom