Electron Configuration PDF - Chemistry Questions & Answers

Warm up Activity 1. Define the mass number of an element 2. What is the atomic number of calcium 3. Calculate the number of neutrons in Silicon  The Atom Learning Goals Recognise and compare the relative energies of s, p, and d orbitals. Apply principles (Aufbau,...

Warm up Activity 1. Define the mass number of an element 2. What is the atomic number of calcium 3. Calculate the number of neutrons in Silicon  The Atom Learning Goals Recognise and compare the relative energies of s, p, and d orbitals. Apply principles (Aufbau, Hund’s rule, and Pauli exclusion) to determine electron configurations. Success Criteria I Can: Compare and rank the relative energies of s, p, and d orbitals and explain their significance. Construct full and condensed electron configurations for elements and ions up to Z=36 Electron Configuration Unit 1 Topic 1 Chapter 3.4 State the relative energies of the s, p and d orbitals. Electron Configurations Electron configurations shows where the electrons are located within an atom Each energy level or shell surrounding an atom is given a letter (s, p, d and f). A breakdown of each energy level capacity is shown in Table 1 Each orbital can hold up to 2 electrons Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to write electron configurations for atoms and ions up to Z = 36 Electron Configurations Electron configurations are based primarily on three principles: - Aufbau principle - Pauli exclusion principle - Hund’s rule http://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/Hund%2CFriedrich_1920er_G%C3%B6ttingen.jpg/225px-Hund%2CFriedrich_1920er_G%C3%B6ttingen.jpg Neils Bohr Wolfgang Pauli Friedrich Hund Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to write electron configurations for atoms and ions up to Z = 36 Aufbau Principle Electrons occupy the lowest energy orbitals (or shells) first. Principle energy level (n = 1,2,3,…) corresponds to the energy levels of an electron within an atom. Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to write electron configurations for atoms and ions up to Z = 36 Electron Configuration Each principal energy level is divided into sub-levels (e.g., s, p, etc). In each sublevel the electrons are found within specified orbitals. sublevel The order of energy levels and sublevels when creating an electron configuration is as follows: Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to write electron configurations for atoms and ions up to Z = 36 Electron Configuration Q) Determine the full electron configuration of silicon Solution Silicon has 14 electrons. Beginning at 1s, the full electron configuration is: Sub-levels s p d f Contains 1 orbital Contains 3 orbitals Contains 5 orbitals Contains 7 orbitals Starts at the 1st principal Starts at the 2nd principal Starts at the 3rd principal Starts at the 4th principal energy level energy level energy level energy level State the relative energies of the s, p and d orbitals. Sub-levels s p d f Contains 1 orbital Contains 3 orbitals Contains 5 orbitals Contains 7 orbitals Spherical shaped 3 different tear shapes 5 different shapes 7 different shapes Starts at the 1st principal Starts at the 2nd principal Starts at the 3rd principal Starts at the 4th principal energy level energy level energy level energy level Each orbital can hold 2 electrons. State the relative energies of the s, p and d orbitals. Check-in If each orbital (region of space) can hold maximum 2 electrons, determine how many electrons can fit in: a. The s orbital b. The p orbitals c. The d orbitals d. The f orbitals Determine full and condensed electron configurations for atoms and ions up to Z = 36. Question 1) Write the electron configuration of the following elements: a) Sodium b) Magnesium c) Boron d) Neon e) Sulfur State the relative energies of the s, p and d orbitals. Layout of the Periodic table The energy sublevel filled (or partially filled) last will align with the location of that element within the periodic table Example: Phosphorus is located in the p block; therefore electron configuration should end at 3p. Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to write electron configurations for atoms and ions up to Z = 36 and use orbital diagrams to represent the character and relative energy of orbitals Electron Configurations Electron configurations for Magnesium: 1s22s22p63s2 They can also be written as condensed electron configurations: [Ne]3s2 Rule Check for the closest noble gas (Check to the left of the element) Write this in square brackets and then state the location of the remaining outer electrons in the atom Electron configuration for Chlorine: Recall the relative energies of the s, p and d orbitals in energy levels to construct electron configurations for atoms and ions up to Z = 36 and recognise that the periodic table is arranged into four blocks associated with the four sub-levels — s, p, d and f Aufbau/ Orbital Diagrams This is a visual representation of electron configurations They give more information specific to the individual electrons involved Each square represents an orbital and sublevels that contain more than one orbital appear together. Example: d sublevels contain 5 orbitals, so there will be 5 squares there  6p 5d 4f 6s 5p 5s 4d Increasing energy 4p 3d 4s These are the 3p Principle Energy Levels 3s n=3 2p 2s n=2 n=1 1s Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to write electron configurations for atoms and ions up to Z = 36 Pauli Exclusion Principle Each orbital can hold a maximum of two electrons. This means that an orbital can contain 0,1, or 2 electrons Each electron appears to be spinning on an axis. The spin can only be in two directions, represented as up and down arrows (↑↓). The first electron to enter the orbital is drawn as an upwards pointing half-arrow. The second electron must have an opposing direction to the first electron. Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to write electron configurations for atoms and ions up to Z = 36 Hund’s Rule One electron enters each orbital until all contain an electron with the same spin direction. Thereafter, a second electron in the opposite direction can enter any of the orbitals Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to write electron configurations for atoms and ions up to Z = 36 Electron Configurations (Orbital diagrams not assessed) Draw the electron configuration for oxygen. Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to write electron configurations for atoms and ions up to Z = 36 and use orbital diagrams to represent the character and relative energy of orbitals Electron Configurations (Orbital diagrams not assessed) Draw the electron configuration for sodium.