Which of the foEowing statements regarding an anion is not true?a)The ...
The effective nuclear charge decreases when an anion is formed due to increase in number of electrons.
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Which of the foEowing statements regarding an anion is not true?a)The ...
The statement that is not true is option C: The effective nuclear charge increases when an anion is formed.
An anion is a negatively charged ion that is formed when an atom gains one or more electrons. When an atom gains an electron, it becomes negatively charged because the number of protons in the nucleus remains the same while the number of electrons increases. Here's an explanation of why the other statements are true:
a) The gain of an electron leads to the formation of an anion:
When an atom gains one or more electrons, it becomes negatively charged and forms an anion. This occurs because the atom now has more electrons than protons, resulting in a negative charge.
b) The radius of the anion is larger than the atomic radius of its parent atom:
When an atom gains an electron to form an anion, the additional electron(s) occupy an outer electron shell. This increases the electron-electron repulsion, causing the electron cloud to expand. As a result, the radius of the anion is larger than the atomic radius of its parent atom.
d) The electron cloud expands due to increased repulsion among the electrons:
As mentioned above, when an atom gains an electron to become an anion, the electron-electron repulsion increases. Electrons are negatively charged particles, and the repulsion between them causes the electron cloud to expand. This expansion is responsible for the larger radius of the anion compared to its parent atom.
c) The effective nuclear charge increases when an anion is formed:
The effective nuclear charge refers to the attractive force experienced by the electrons in an atom or ion. It is determined by the number of protons in the nucleus and the shielding effect of the inner electron shells. When an atom gains an electron to form an anion, the number of electrons increases, but the number of protons in the nucleus remains the same. As a result, the effective nuclear charge experienced by the electrons decreases, not increases. The additional electron(s) also provide additional shielding effect, further reducing the effective nuclear charge.
Therefore, option C is not true because the effective nuclear charge actually decreases when an anion is formed.
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