Which ion in the pair has greater charge density? Explain Choice. Magnesium ion or Barium ion
Charge density is the charge/unit volume. Since Mg^2+ ion is smaller than the Ba^2+, the Mg will have the greater charge density; i.e., a 2+ charge spread over a smaller volume.
To determine which ion has greater charge density, we need to compare the charges and sizes of the ions in question.
Magnesium ion (Mg²⁺): This ion has a charge of 2+ since it has lost two electrons from its neutral magnesium atom. The atomic number of magnesium is 12, indicating that it has 12 protons in its nucleus.
Barium ion (Ba²⁺): This ion also has a charge of 2+ because it has lost two electrons from its neutral barium atom. The atomic number of barium is 56, indicating that it has 56 protons in its nucleus.
Now, let's compare their sizes. The size or radii of ions typically decrease as we move across a period from left to right in the periodic table, and they increase as we move down a group. Since magnesium and barium are in the same group (group 2A), the barium ion (Ba²⁺) will have a larger atomic size than the magnesium ion (Mg²⁺) due to the increase in atomic size as we move down the group.
Considering the charge and size factors, the magnesium ion (Mg²⁺) will have a higher charge density compared to the barium ion (Ba²⁺). This is because the charge is concentrated on a smaller size cation in the case of the magnesium ion.
In summary, the magnesium ion has a greater charge density than the barium ion due to its smaller size and the same charge.
To determine which ion has greater charge density between magnesium (Mg2+) and barium (Ba2+), we need to understand what charge density refers to.
Charge density is the ratio of the ion's charge to its volume. It represents the concentration of charge within a given space. A higher charge density indicates a greater concentration of charge within a smaller area.
Both magnesium and barium ions have a charge of +2 (Mg2+ and Ba2+), so we can focus on comparing their sizes.
The size of an ion is influenced by its atomic number and electron configuration.
Magnesium, with an atomic number of 12, has a stronger nuclear charge than barium, which has an atomic number of 56. The stronger nuclear charge in magnesium attracts the electrons more strongly, resulting in a tighter electron cloud and a smaller ionic radius compared to barium.
Thus, magnesium ion (Mg2+) has a smaller ionic radius, and since charge density is inversely proportional to ionic radius, it means that magnesium ion has a higher charge density compared to barium ion (Ba2+).
Therefore, the magnesium ion has a greater charge density than the barium ion.