Barium is a chemical element with the symbol Ba and atomic number 56. Let’s break down its properties based on the requested information:
a. Atomic Number: Barium has an atomic number of 56, which means it is located in group 2 of the periodic table.
b. Number of Protons, Neutrons, and Electrons in the Neutral Atom: In a neutral atom of barium, the number of protons is equal to the atomic number, which is 56. The number of electrons in a neutral atom also equals the number of protons, so it also has 56 electrons. The most common isotope of barium is Barium-138, which has 82 neutrons (138 – 56 = 82).
c. Number of Valence Electrons: Barium is an alkaline earth metal, and it has 2 valence electrons. These electrons are located in the outermost shell, which is the 6s shell for barium.
d. Tendency to Gain or Lose Valence Electrons: Barium tends to lose its 2 valence electrons when it reacts, forming a cation with a +2 charge. This behavior is typical for alkaline earth metals, which prefer to lose electrons to achieve a stable electron configuration similar to the nearest noble gas.
e. Charge on the Ion: When barium loses its 2 valence electrons, it forms a positive ion with a charge of +2 (Ba2+). This positive charge is a result of having more protons than electrons after the loss of the valence electrons.
In summary, barium has the following properties: atomic number 56, 56 protons, 82 neutrons, 56 electrons in a neutral state, 2 valence electrons, a tendency to lose 2 electrons, and a +2 charge when it forms an ion.