How many total and how many valence electrons are in the following neutral atom? barium (Ba) Total electrons: Valence electrons: eTextbook and Media Save for Later
The Correct Answer and Explanation is:
Correct Answer:
- Total electrons in Barium (Ba): 56
- Valence electrons in Barium (Ba): 2
Explanation
Barium (Ba) is a chemical element with an atomic number of 56. This atomic number represents the number of protons found in the nucleus of a barium atom. In a neutral atom, the number of electrons is equal to the number of protons. Therefore, a neutral barium atom contains 56 total electrons.
To identify how many of these electrons are valence electrons, the electronic configuration must be analyzed. The full electron configuration of barium is:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s²
This arrangement shows how electrons are distributed among the various atomic orbitals. The outermost shell, also known as the valence shell, is the one with the highest principal quantum number. In barium’s case, the sixth energy level (6s²) is the outermost shell. The electrons in this shell are considered valence electrons because they are involved in chemical bonding and reactivity.
Since the 6s orbital contains 2 electrons, barium has 2 valence electrons.
Valence electrons determine the chemical behavior of an element. For barium, the presence of two electrons in the outer shell makes it similar in reactivity to other elements in Group 2 of the periodic table, known as the alkaline earth metals. These elements typically lose their two valence electrons to achieve a stable electron configuration, forming ions with a 2+ charge (Ba²⁺).
In summary, the neutral barium atom contains 56 total electrons and 2 valence electrons, with the latter located in the outermost 6s orbital. This configuration directly influences its chemical properties, such as its tendency to form ionic compounds by donating its valence electrons.
