GC1 Lesson 3 Atomic Structure.pdf

General Chemistry 1 Teacher: Ms.Abegail R. Sacabon, LPT  Unit 1 Lesson 3 ATOMIC STRUCTURE  Agenda: Objectives of the Lesson Key Take Aways PhET Simulation Assessment Discussion Performance Task Seatwork: Activity 3.2...

General Chemistry 1 Teacher: Ms.Abegail R. Sacabon, LPT  Unit 1 Lesson 3 ATOMIC STRUCTURE  Agenda: Objectives of the Lesson Key Take Aways PhET Simulation Assessment Discussion Performance Task Seatwork: Activity 3.2 Project  OBJECTIVES OF THE LESSON 1. Differentiate among atomic number, mass number, and isotopes, and which of these distinguishes one element from another. 2. Calculate the atom weight and atomic number from protons, neutrons and electrons. 3. Write isotopic symbols and give examples  PERFORMANCE TASK The learners are able to Design using multimedia, demonstrations, or models, a representation or simulation of atomic structure atomic models using PHET Simulation PHET SIMULATION Scan the following code to access the simulation Build an atom  Process questions: 1. What happened to the element/s when you add protons in the nucleus? 2. What happened to the element/s when you remove protons in the nucleus? 3. What is the role of protons in an atom?  An atom is made up of 3 subatomic particles: Protons (p+)– positive particle found in the Nucleus of the atom Neutrons (n 0)- neutral particles also found in the middle of the atom Electron (e-) – negatively charged particles found orbiting the protons and neutrons (the Nucleus) Subatomic particles Mass (g) proton 1.67 X 10-24 neutron 1.67 X 10-24 electron 9.11 X 10-28 0.00091 X 10-24  Atomic mass unit (amu) It is equal to one-twelfth (1/12) of the mass of the carbon atom 1 amu=1.67 X -24 10 g 1 Carbon atom= 6 protons + 6 neutrons= 12 12 amu  ATOMIC NUMBER (Z) ❑ >The number of protons of an element ❑ >The corresponding number of the element in the periodic table The atomic number tells you the number of protons in an atom’s nucleus! Equation 2. Z= p If you change the number of protons, you change the ELEMENT!  ATOMIC NUMBER (Z) For an Element, # of protons (p+) = # of electrons (e-) So, their charges are NEUTRAL PHET SIMULATION Scan the following code to access the simulation Build an atom  Process questions: 1. What happened to the elements if the number of electrons is the same as the number of protons? 2. What happened to the elements if there are excess electrons? 3. What happened to the elements if there are lacking or less electrons?  Nucleus The core center of the atom Protons and Neutrons combine to form the Nucleus. The electrons orbit in circles called ELECTRON SHELLS.  MASS NUMBER (A) The number of protons + number of neutrons Mass of the nucleus Atomic mass or atomic weight (periodic table) Equation 1. A= p + n  What about the neutrons? Neutrons are within the atom’s nucleus and have no electrical charge !! (Their symbol is: n o) Again…neutrons and protons give an atom its mass, so to calculate number of neutrons in an atom: o Equation 3. n = A-Z  What about the electrons? Remember for an atom to be neutral: the number of p is equal to the number of e Therefore, Equation 4. Z= p= e  An atom with excess electrons is negatively- charged An atom lacking electrons is positively- charged Process questions: 1. What happened to the elements if the number of electrons is the same as the number of protons? 2. What happened to the elements if there are excess electrons? 3. What happened to the elements if there are lacking or less electrons? Process questions: 1. What happened to the elements when you add neutrons in the nucleus? 2. What happened to the elements when you remove neutrons in the nucleus?  ISOTOPES Elements having the same number of protons but differ in number of neutrons Ex. The isotopes of Carbon  Examples of ISOTOPES ❑ Carbon 14 - used in dating of fossils ❑ Uranium 235 Carbon Dating - used in nuclear reactors to produce electricity ❑ Nitrogen 15 - used to determine the diet of the organisms ❑ Cobalt-60 - used in chemotherapy Cobalt-60 Isotope  Writing Isotopic symbols A 1. Z SAMPLE PROBLEM Complete the ff table Element Atomic Mass Number of Number Number protons electrons neutrons Nitrogen 7 14 7 SAMPLE PROBLEM Complete the ff table Element Atomic Mass Number of Number Number protons electrons neutrons Nitrogen 7 14 7 7 7 SAMPLE PROBLEM Complete the ff table Element Atomic Mass Number Number protons electrons neutrons Zinc 30 35 SAMPLE PROBLEM Complete the ff table Element Atomic Mass Number Number protons electrons neutrons Zinc 30 65 30 30 35 SAMPLE PROBLEM Complete the ff table Element Atomic Mass Number Number protons electrons neutrons Radon 86 136 SAMPLE PROBLEM Complete the ff table Element Atomic Mass Number Number protons electrons neutrons Mg2+ 12 24 12 10 12 N3- 7 14 7 10 7 Cl- 17 35 17 18 18 K+ 19 39 19 40 20 SAMPLE PROBLEM Complete the ff table Element Atomic Mass Number Number protons electrons neutrons Carbon-14 6 14 6 Iodine-131 53 78 Sulfur-36 36 17 Palladium 46 105 46  SEATWORK My Skill Builder page 26 Parts A, B and C  Key Takeaways Atoms are the smallest particles of matter which are composed of protons, neutrons and electrons. The number of protons determines the atomic number (Z) of an element, while the sum of protons and neutrons determines the mass number (A) of the nucleus or the atom. Elements having the same number of protons but different in number neutrons are called isotopes  Key Takeaways The charge of the atom depends on the number of electrons. Excess of electrons forms a negatively charged atom (anion) while lack of electrons forms a positively charged atom (cation). An atom having the same number of protons and neutrons are considered neutral.  ASSESSMENT Direction: Identify what is being described in the statements below. 1. It is the number of protons. 2. It is the center of the atom composed of protons and neutrons 3. It is the number of protons and neutrons. 4. These are elements of same atomic number but with different number of neutrons 5. It is the subatomic particle that determines the charge of the atom  Answers to Assessment 1. It is the number of protons. Atomic number or Z 2. It is the center of the atom composed of protons and neutrons. Nucleus 3. It is the number of protons and neutrons. Mass number or A 4. These are elements of same atomic number but with different number of neutrons. Isotopes 5. It is the subatomic particle that determines the charge of the atom. Electron PERFORMANCE TASK (INDIVIDUAL)