1724374923_1707410100_1695082926_BIOL111_L4.pdf

COURSE: INTRODUCTION TO BIOLOGICAL CONCEPTS COURSE CODE: BIOL 111 CREDIT HOURS: 3 LECTURER : GERLISA VIGILANT SEPTEMBER 2022/2023 SEMESTER Chemistry of living organisms  Learning Objectives 1. Define the terms atoms, elements and molecules (also state examples) 2. Explain the s...

COURSE: INTRODUCTION TO BIOLOGICAL CONCEPTS COURSE CODE: BIOL 111 CREDIT HOURS: 3 LECTURER : GERLISA VIGILANT SEPTEMBER 2022/2023 SEMESTER Chemistry of living organisms  Learning Objectives 1. Define the terms atoms, elements and molecules (also state examples) 2. Explain the subatomic structure of atoms (protons, neutrons, electrons) 3. Interpret atomic number, mass number/atomic mass. 4. State the number of atoms in a given element of a compound.  Learning Objectives 1. Calculate the number of subatomic particles, given relevant information 2. Name the first ten elements in the periodic table 3. Draw the electronic configuration of the first ten elements in the periodic table 4. Calculate the charge of the first ten elements in the periodic table.  Video links! https://www.youtube.com/watch?v=h6LPAwAmnCQ https://www.youtube.com/watch?v=_S7ov25y3_M https://www.youtube.com/watch?v=7VZApOzxYC4 https://www.youtube.com/watch?v=R5XLelMDYTw Elements and Compounds Matter is made up of elements An element is a substance that cannot be broken down to other substances by chemical reactions A compound is a substance consisting of two or more elements in a fixed ratio Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 2-3 Sodium Chlorine Sodium chloride Concept 2.2: An element’s properties depend on the structure of its atoms Each element consists of unique atoms An atom is the smallest unit of matter that still retains the properties of an element. A molecule is made up of one or more Atoms. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Subatomic Particles Atoms are composed of subatomic particles Relevant subatomic particles include: – Neutrons (no electrical charge) – Protons (positive charge) – Electrons (negative charge) Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings  Neutrons and protons form the atomic nucleus Electrons form a cloud around the nucleus Neutron mass and proton mass are almost identical and are measured in daltons Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 2-5 Cloud of negative charge (2 electrons) Electrons Nucleus (a) (b) Atomic Number and Atomic Mass Atoms of the various elements differ in number of subatomic particles An element’s atomic number is the number of protons in its nucleus An element’s mass number is the sum of protons plus neutrons in the nucleus Atomic mass, the atom’s total mass, can be approximated by the mass number Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Energy Levels of Electrons Energy is the capacity to cause change Potential energy is the energy that matter has because of its location or structure The electrons of an atom differ in their amounts of potential energy An electron’s state of potential energy is called its energy level, or electron shell Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 2-8 (a) A ball bouncing down a flight of stairs provides an analogy for energy levels of electrons Third shell (highest energy level) Second shell (higher Energy energy level) absorbed First shell (lowest energy level) Energy lost Atomic (b) nucleus Electron Distribution and Chemical Properties The chemical behavior of an atom is determined by the distribution of electrons in electron shells The periodic table of the elements shows the electron distribution for each element Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings  Valence electrons are those in the outermost shell, or valence shell The chemical behavior of an atom is mostly determined by the valence electrons Elements with a full valence shell are chemically inert Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Draw electronic configuration of : Electron distribution of elements How to calculate the number of subatomic particles Atomic number = Number of protons Atomic number = Number of electrons Mass number = Protons plus neutrons Number of Neutrons =? Example Carbon- Atomic Number=6 Mass number=12 Protons? Neutrons? Electron? Example Calculate the number of neutrons, protons and electrons in Fluorine Mass # =19 Anomic # =9 How to calculate the charge of an element https://youtu.be/xz14VaLMw1U Lets do some examples!!! Example Example How to calculate the number of atoms in a molecule H2O C2H4O2 (NH3)2