Ph113 | Activity 5 (Pre-Lab) Pt.1

Summary

This transcript delves into the fundamentals of electron configuration and quantum numbers, explaining how electrons are distributed in atomic orbitals and how these distributions follow a specific sequence. It covers the basics of filling orbitals (s, p, d, f subshells) and how to write electron configurations for elements, with examples like sodium (Na) and chlorine (Cl). The discussion extends to quantum numbers, including principal quantum number (n), which indicates the energy level, and angular momentum quantum number (l), which defines the shape of orbitals. It also touches on the effect of atomic charges on electron configurations.

Takeaways

• 😀 Electron configuration summarizes the distribution of electrons around the nucleus of an atom, with electrons found in orbitals surrounding the nucleus.
• 😀 The S subshell can hold 2 electrons, P can hold 6, D can hold 10, and F can hold 14 electrons, based on the number of orbitals each subshell has.
• 😀 The electron configuration starts with 1s, 2s, 2p, 3s, 3p, 4s, 3d, and so on. The order follows a specific sequence based on orbital filling rules.
• 😀 In a neutral atom, the number of protons equals the number of electrons, and the atomic number of an element indicates the number of electrons.
• 😀 When dealing with charged atoms (ions), the electron configuration must be adjusted. For positive ions, electrons are subtracted; for negative ions, electrons are added.
• 😀 Sodium (Na) has an atomic number of 11, and its electron configuration is 1s² 2s² 2p⁶ 3s¹.
• 😀 Chlorine (Cl) has an atomic number of 17, and its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁵.
• 😀 Copper (Cu) has an atomic number of 29, and its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁹.
• 😀 Quantum numbers describe the properties of electrons in orbitals, including the energy level, shape, and orientation of the orbital.
• 😀 The principal quantum number (n) indicates the energy level (shell) of an electron, with possible values from 1 to 7 corresponding to the periods in the periodic table.

Q & A

What is electron configuration?

Electron configuration is a summary of how electrons are distributed around the nucleus of an atom. It shows the arrangement of electrons in different orbitals, and is typically represented using the notation 1s, 2s, 2p, 3s, etc.

How do we write electron configurations for elements?

To write electron configurations, you start with the 1s orbital and move through the s, p, d, and f orbitals in sequence, based on the number of electrons in the atom. For example, sodium (Na) with atomic number 11 has the electron configuration 1s2 2s2 2p6 3s1.

Why does the 1s orbital hold only two electrons?

The 1s orbital can only hold two electrons because it consists of a single orbital, and each orbital can accommodate a maximum of two electrons.

What is the maximum number of electrons that can be held by the p subshell?

The p subshell can hold a maximum of six electrons because it consists of three orbitals, each of which can hold two electrons.

How do you determine the electron configuration for a charged atom?

For a charged atom, the electron configuration is determined by adjusting the number of electrons based on the charge. A positive charge indicates a loss of electrons, while a negative charge indicates a gain of electrons.

What is the principal quantum number (n) and what does it represent?

The principal quantum number (n) represents the energy level or shell of an orbital. It also indicates the size of the orbital. For example, in sodium (Na), the principal quantum number is 3, meaning the third energy level is occupied by electrons.

What are the possible values for the angular momentum quantum number (l)?

The angular momentum quantum number (l) can have values from 0 to n-1, where n is the principal quantum number. The values of l correspond to the different subshells: 0 for s, 1 for p, 2 for d, and 3 for f.

What is the shape of the orbital for the s subshell?

The shape of the orbital for the s subshell is spherical.

What is the shape of the orbital for the p subshell?

The shape of the orbital for the p subshell is described as a dumbbell.

How does the electron configuration of chlorine (Cl) differ from that of sodium (Na)?

Chlorine has an atomic number of 17, so its electron configuration is 1s2 2s2 2p6 3s2 3p5, whereas sodium, with atomic number 11, has the electron configuration 1s2 2s2 2p6 3s1. Chlorine has more electrons in the 3p orbital.