Chemistry for Engineers 1: The Periodic Table PDF

Chemistry for Engineers 1 THE PERIODIC TABLE in l, 2=d OF ELEMENTS MPS Department  FEU Institute of Technology  OBJECTIVES ∎ Define the basic ideas of quantum number and the periodic classification of elements. ∎ Differentiate between...

Chemistry for Engineers 1 THE PERIODIC TABLE in l, 2=d OF ELEMENTS MPS Department  FEU Institute of Technology  OBJECTIVES ∎ Define the basic ideas of quantum number and the periodic classification of elements. ∎ Differentiate between energy levels, subshells, and atomic orbital. ∎ Illustrate the quantum numbers and electronic configuration.  Chemistry for Engineers 1 Quantum Theory and The History of Periodic Table MPS Department  FEU Institute of Technology  Quantum Mechanics – primarily based on the wave properties of matter and it describes the behaviour of very small particles. https://www.researchgate.net/figure/Hydrogen-atomic-orbitals-represented- as-probability-density-plots-The-darker-the_fig1_228078714  Basic Ideas of Quantum Mechanics 1. Atoms and molecules can exist only in certain energy states. In each energy state, the atom or molecule has definite energy. 2. When atoms or molecules emit or absorb radiation, they change their energies. 3. The allowed energy states of atoms and molecules can be described by sets of QUANTUM NUMBERS.  Energy Level, Subshells & Atomic Orbital Energy Levels - also referred to as electron shells. - a region in space in which the probability finding an electron is high. Energy Sublevels (Subshells) - a subdivision of the electron shells. Atomic Orbital – region in space where there is a significant probability of finding a particular electron. – sometimes referred to as an electron cloud. Electrons in each Energy Levels Energy Level, Subshells & Atomic Orbital n= principal quantum number https://chemistryonline.guru/aufbau- principle/au2/  Principal Quantum Numbers Principal Quantum Number, n - describes the main energy level or shell, that an electron occupies. - it may be a positive energy: n = 1, 2, 3, 4.... https://flexbooks.ck12.org/cbook/ck-12-chemistry- flexbook-2.0/section/5.12/primary/lesson/energy- level-ms-ps Angular Momentum Quantum Number or known as Azimuthal Quantum Number https://socratic.org/questions/55ed bc8b581e2a3e01c9ff20  Magnetic Quantum Numbers https://byjus.com/physics/magnetic-quantum- number/  Magnetic Quantum Numbers Magnetic Quantum Number, ml – designates a specific orbital within a subshell. – Note that orbitals within a given subshell differ in their orientations in space, but not in their energies. The magnetic quantum number is defined by any integral values from - l through 0 to + l. ml = - l ,..., 0 ,..., l  Spin Quantum Numbers Spin Quantum Number, ms – refers to the spin of an electron and the orientation of the magnetic field produced by this spin. For every set of n, l, ml, ms is: ms = ± ½  Spin Quantum Numbers Number of boxes to use on testing shifts of orbitals (refer to slide 11) in l, 2=d (pls refer on Angular Momentum / Azimuthal Quantum Number) https://chem16helper.wordpress.com/2015/07 /04/quantum-numbers-and-isotopes/  Guiding Principles Aufbau Principle - electrons orbiting one or more atoms fill the lowest available energy levels before filling higher levels. Hunds Rule - electrons occupy all the orbital of a given subshell singly before pairing begins. Pauli Exclusion Principle - states that no two electrons in an atom may have identical sets of four quantum numbers.  Aufbau Principle Electrons are assigned to orbitals in order of increasing value of (n + l). For subshells with the same value of (n+l), electrons are assigned first to the subshell with lower n. https://www.pinterest.ph/pin/174584923031805012/  Hund’s Rule https://www.quora.com/Why-does-platinum%E2%80%99s-electron- configuration-not-conform-to-Hund%E2%80%99s-rule-i-e-have-a-full- 5D-orbital-as-other-metals-in-its-group-do-e-g-palladium  Pauli Exclusion No two same elements can have the same set of quantum numbers. https://www.chegg.com/homework-help/questions-and-answers/orbital- filling-diagram-violates-pauli-exclusion-principle-q5805193  Summary of Principles No more than two electrons can occupy one orbital. Electrons occupy the lowest possible energy sublevels; they enter a higher sublevel only when the lower sublevels are filled. Orbitals in a given sublevel of equal energy are each occupied by a single electron before a second electron enters them. Example: Give the possible Quantum Nos. for electrons in the 1st MEL: 1 n l ml ms 1s 1 0 0 +1/2 ( H) 2 1s 1 0 0 - 1/2 ( He) Give the possible Quantum Nos. for electrons in the 2nd MEL: n  m ms ( 2 S ) 1 2 0 0 +1/2 2s 2 0 0 - 1/2 2s 2 n  m ms (6p) 2p 1 2 1 -1 +1/2 2 1 0 + 1/2 2 p2 2 p3 2 1 +1 +1/2 2 p4 2 1 -1 - 1/2 2 p5 2 1 0 -1/2 2 p6 2 1 +1 - 1/2  Try This! Draw the following Quantum Numbers. Identify if each given nos. is possible. 1. n = 2, l = 1, ml = -1, ms = +½ 2. n = 1, l = 2, ml = 2, ms = -½ 3. n = 2, l = 1, ml = -1, ms = -½ Possible Not Possible Depends on the total number of arrows inside the boxes  Arrangement of Electrons Electron Configuration – assignment of all of the electrons in an atom into specific shells and subshells. – Designation Shell = principal quantum number, n Subshell = angular quantum number, (s, p, d or f) Number of electrons = superscript number Principal quantum number of Number of electrons in the shell (n=3) subshell 3p5 Subshell  Electronic Configuration https://opentextbc.ca/chemistry/chapter/6-4-electronic- structure-of-atoms-electron-configurations/  Electronic Configuration For convenience, the following core symbols are used  Try This! Find the Electronic Configuration of the following Elements – Lithium – Carbon – Phosphorus – Neon – Xenon  PERIODIC TABLE Periodic Law – States that when elements are arranged in order of increasing atomic number, their physical and chemical properties show a periodic pattern Periodic Table – Each rows are called Periods – Each column are called Groups or Families which shares similar chemical properties http://rogersphysicalscience.weebly.com/chem istry-facts-for-the-exam.html  Grouping the Elements Classification of Elements – Noble Gases (Group 8A) also known as Inert Gases because no chemical reactions were known for them. – Representative Elements (A Group) Their last electron is assigned to an outer shell s or p orbital.  Grouping the Elements Classification of Elements by Block – Transition Elements/Metals (B Group) also known as D-transition elements. characterized by their electrons filling the d orbital. – Inner Transition Element/Metal also known as F-Transition Elements. characterized by their electron filling the f orbital.  s-, p-, d-, and f- block elements Representative Elements (s and p block) Transition Elements/Metals (d block) Inner Transition Metals (f block) https://saintschemistry10.weebly.co m/electron-configuration.html  Chemistry for Engineers 1 Periodic Variations of Elements MPS Department  FEU Institute of Technology  OBJECTIVES ∎ Determine the periodic variations of elements in physical properties. ∎ Differentiate the periodic trends as increasing, or decreasing from left to right or from top to bottom.  Periodic Properties of Elements Periodic Trends / Periodicity – specific patterns that are present in the periodic table that illustrate different aspects of a certain element. – Periodic Classification: Atomic Radius Ionization Energy Electron Affinity Ionic Size Electronegativity  Atomic Radius Atomic Radius – primarily the radius of an element. – Trend increase from top to bottom along a group or family. decrease from left to right across a period. https://www.ck12.org/book/ck-12-chemistry- second-edition/r15/section/9.2/  Periodicity of Elements Ionization Energy, IE – the energy required to remove an electron from an atom. – can be thought of how strongly an atom holds onto its outermost electron. – Trend decrease from top to bottom in groups and families. gradual increase from left to right (with some irregularities.  IONIZATION ENERGY https://www.mikeblaber.org/oldwine/chm104 5/notes/Periodic/Ionize/Period04.htm  Electron Affinity - the amount of energy released or absorbed when an electron is added to an atom to form a negative ion. – a measure of the attraction of an atom for an electron or the atom’s tendency to form a negative ion. Electron Affinity of Helium and Chlorine He(g) + e- → He-(g) EA = 0 kJ/mol Cl(g) + e- → Cl-(g) +349 kJ EA = -349 kJ/mol  Electron Affinity https://www.mikeblaber.org/oldwine/chm104 5/notes/Periodic/Affinity/Period05.htm  IONIC SIZE Ionic Size – the size of an atom’s ion. Isoelectronic Species – have the same number of electrons, thus, they have the same electronic configurations. – differs in the nuclear charges.  IONIC SIZE https://socratic.org/questions/what-is-the- difference-between-the-ionic-radius-and-the- atomic-radius-of-an-elem  ELECTRONEGATIVITY Electronegativity, EN – the attractive force of an element for a shared pair of electrons in a molecule. – Trend in l, 2 non Metals form anion by gaining electron high electronegativity. metals form cation by losing electron low electronegativity. increases from left to right along the period. decreases from top to bottom in groups or families.  ELECTRONEGATIVITY https://www.researchgate.net/figure/Periodic- chart-of-the-computed-electronegativity- values-of-103-elements_tbl1_265786241  Summary of Periodic Trends From Left to Right From Top to Bottom Periodic Trend (Period) (Group) Atomic Radius* Decrease Increase Ionization Energy* Gradual Increase** Decrease Electron Affinity* Increase Decrease Ionic Size*** - - Electronegativity* Increase Decrease THANK YOU… GOD BLESS…  REFERENCES Lawrence S. Brown and Thomas A. Holme (2018), Chemistry for Engineering Students : Cengage Learning Roxy Wilson (2018), Solutions to Red Exercises: Chemistry: The Central Science : United Kingdom: Pearson Theodore E. Brown, et. al.(2018), Chemistry: The Central Science (14th Edition) : United Kingdom: Pearson https://opentextbc.ca/biology2eopenstax/chapter/atoms-isotopes- ions-and-molecules-the-building-blocks/ https://www.rsc.org/periodic-table/history/about https://www.slideshare.net/AbdulAlHafizIsmail/lu5-trends-of- periodic-atomic-properties