Afinitas Elektron (Sifat Periodik Unsur)

Summary

The video explains the concept of electron affinity, which is the energy released or absorbed when an atom gains an electron. Using examples from the periodic table, it illustrates how electron affinity varies across groups and periods. In a group, electron affinity decreases as you move down because atoms have more electron shells and weaker attraction to incoming electrons. In a period, electron affinity increases from left to right due to an increase in nuclear charge. The video compares elements like Fluorine (F), Chlorine (Cl), and Sulfur (S) to demonstrate these trends.

Takeaways

• 😀 Electron affinity refers to the amount of energy released or absorbed when an atom attracts an electron.
• 😀 The greater the ability of an atom to attract an electron, the more energy is released during the process.
• 😀 In a group (vertical column) of the periodic table, electron affinity decreases from top to bottom.
• 😀 Fluorine (F) has a higher electron affinity than chlorine (Cl), as F attracts electrons more strongly.
• 😀 In the case of F (atomic number 9), it has 2 electron shells, whereas Cl (atomic number 17) has 3 shells.
• 😀 The fewer the electron shells an element has, the stronger its attraction to electrons.
• 😀 Chlorine (Cl) has a larger number of protons than fluorine (F), but fluorine’s fewer electron shells make it better at attracting electrons.
• 😀 The trend within a group shows that as you move downward, electron affinity decreases.
• 😀 In a period (horizontal row) of the periodic table, electron affinity increases as you move from left to right.
• 😀 Chlorine (Cl), with 17 protons, has a stronger attraction for electrons than sulfur (S), with 16 protons, due to its larger proton count.
• 😀 Elements with the same number of electron shells but different numbers of protons will have varying electron affinities due to the difference in proton-electron attraction.

Q & A

What is electron affinity?

Electron affinity refers to the amount of energy released or absorbed when an electron is added to a neutral atom. A higher electron affinity means the atom more readily attracts an additional electron.

How does electron affinity change across a group in the periodic table?

Electron affinity decreases as you move down a group in the periodic table. This is because the number of electron shells increases, reducing the attraction between the nucleus and the added electron.

Why does fluorine (F) have a higher electron affinity than chlorine (Cl)?

Fluorine has a higher electron affinity than chlorine because fluorine has fewer electron shells, resulting in a stronger attraction for an added electron compared to chlorine.

How does electron affinity change across a period in the periodic table?

Electron affinity increases as you move from left to right across a period. This is due to an increase in the number of protons, which enhances the atom's ability to attract electrons.

Why does chlorine (Cl) have a higher electron affinity than sulfur (S)?

Chlorine has a higher electron affinity than sulfur because chlorine has more protons, resulting in a stronger pull on the electron being added compared to sulfur, even though both are in the same period.

What role do electron shells play in determining electron affinity?

The number of electron shells affects electron affinity by influencing how strongly the nucleus can attract additional electrons. Atoms with fewer shells have a stronger attraction for electrons.

What is the trend in electron affinity when moving from top to bottom in a group?

The trend is that electron affinity becomes smaller as you move down a group. This is because the added electron is farther from the nucleus due to the increasing number of electron shells.

Can two elements in the same group have different electron affinities?

Yes, elements in the same group can have different electron affinities depending on their size and number of electron shells. For example, fluorine and chlorine both belong to Group 17, but fluorine has a higher electron affinity.

How does the nuclear charge (number of protons) affect electron affinity?

The nuclear charge directly affects electron affinity. More protons in the nucleus lead to a stronger positive charge, which in turn pulls electrons in more strongly, resulting in a higher electron affinity.

What conclusion can be made about the trend of electron affinity across periods and groups?

In general, electron affinity increases across periods from left to right and decreases down groups from top to bottom. This is due to changes in nuclear charge and the number of electron shells.