Introduction to Chemistry - Chapter 1 PDF

James T. Shipman Jerry D. Wilson Charles A. Higgins, Jr. Omar Torres Chapter 1 © 2016 Cengage Learning Learning Objectives: Demonstrate understanding about elements, isotopes, nuclear reactions and practical application of Chemistry Show appreciation by recognizing how elem...

James T. Shipman Jerry D. Wilson Charles A. Higgins, Jr. Omar Torres Chapter 1 © 2016 Cengage Learning Learning Objectives: Demonstrate understanding about elements, isotopes, nuclear reactions and practical application of Chemistry Show appreciation by recognizing how elements are important in our daily lives. Create a timeline of events that happened to you since you were born up to the present time © 2016 Cengage Learning Intro  Basic Chemistry Terminologies and Definitions Atom © 2016 Cengage Learning Intro  Basic Chemistry Terminologies and Definitions Compound © 2016 Cengage Learning Intro  Basic Chemistry Terminologies and Definitions Molecule © 2016 Cengage Learning Intro  Basic Chemistry Terminologies and Definitions Ion © 2016 Cengage Learning Intro Atomic Theory © 2016 Cengage Learning Section 10.1 Discovering Structure of an Atom © 2016 Cengage Learning Section 10.1 Democritus’ Atomic Model © 2016 Cengage Learning Section 10.1 Dalton’s Solid Sphere Model © 2016 Cengage Learning Section 10.1 © 2016 Cengage Learning Section 10.1 Thomson’s Plum Pudding Model © 2016 Cengage Learning Section 10.1 Ernest Rutherford(1871 - 1937) © 2016 Cengage Learning Section 10.1  Rutherford’s Nuclear Model Most of the matter of the atom is found in a very small part of the atom called the nucleus. It is very tiny and extremely dense. Like charges repel so the nucleus must have a positive charge. If electrons have a negative charge they could not be in a positively charged nucleus. Electrons must surround the nucleus at a distance. Atoms are mostly empty © 2016 Cengage Learning space with a tiny, massive Section 10.1 Bohr’s Planetary Model © 2016 Cengage Learning Section 10.1  Bohr’s Nuclear Model ” proposed that electrons move in paths at certain distances around the nucleus. He learned that Electrons can jump from a path on one level to a path on another level. Implications Cathode ray tube- TV Wilhem Roentgen- X-rays Marie Curie- radioactivity Antoine Henri Becquerel- photographic film © 2016 Cengage Learning Section 10.1  Subatomic Particles An atom is composed of three subatomic particles: electrons (–), protons (+), and neutrons (neutral) The nucleus of the atom contains the protons and the neutrons (also called nucleons) The electrons surround (orbit) the nucleus Electrons and protons have equal but opposite charges © 2016 Cengage Learning Section 10.2  The Atomic Nucleus Protons and neutrons have nearly the same mass and are 2000 times more massive than an electron Discovery – electron (J.J. Thomson in 1897), proton (Ernest Rutherford in 1918), and neutron (James Chadwick in 1932) Thomson Rutherford Chadwick © 2016 Cengage Learning Section 10.2 Major Constituents of an Atom © 2016 Cengage Learning Section 10.2 Nucleosynthesis © 2016 Cengage Learning Section 10.2  Atomic Number (Z) Atomic Designations – the number of protons in the nucleus; always the same for a given element – defines the element – also designates the number of electrons in an element Mass Number (A) – protons + neutrons – the total number of nucleons © 2016 Cengage Learning Section 10.2 Bohr’s Nuclear Model © 2016 Cengage Learning Section 10.1 Determining the Composition of an Atom (Example) Determine the number of protons, electrons, and neutrons in the 199 F (fluorine atom). Atomic Number (Z) = 9 \ protons = 9 & electrons = 9 Mass Number (A) = 19 A = N + Z {N = neutron number} \ N = A – Z = 19 – 9 = 10 neutrons = 10 © 2016 Cengage Learning Section 10.2  Atomic Review Protons & Neutrons – in nucleus Electrons – orbit around nucleus (electron cloud) Mass Number (A) = protons + neutrons Atomic Number (Z) = number of protons Neutron Number (N) = number of neutrons Isotope – an element with different number of neutrons (same number of protons) © 2016 Cengage Learning Section 10.2 Completing the Subatomic of Particles A = no. of protons + neutrons Z = no. of protons Protons = Electrons Neutrons = A - Z © 2016 Cengage Learning Practice Exercise 1 Instruction: – Complete the table below Element Mass Atomic Protons Neutrons Electrons Symbol Number Number C 12 6 6 6 6 Cf 251 98 98 153 98 U 238 92 92 146 92 Pb 207 82 82 125 82 © 2016 Cengage Learning Section 10.2 Practice Exercise 1 © 2016 Cengage Learning © 2016 Cengage Learning  Periodic Table of Elements 💡Serves as a repository of information of more than a hundred elements 💡Elements are arranged in increasing atomic number 💡Based on number of outermost ground state electron configuration of an element as well as the element’s chemical properties. © 2016 Cengage Learning Periodic Table of Elements © 2016 Cengage Learning  Periodic Table of Elements a. IUPAC – 1 to 18 b. North American chemists – 1A to 8A; 1B to 8B c. Roman Numerals - “IIA” instead of “2A” © 2016 Cengage Learning  Periodic Table of Elements Three General Classifications 1. The A Group Elements (longer columns) – Representative or main group elements 2. The B Group Elements (shorter columns) – Transition elements 3. The Inner Transition Elements – 2 long rows at the lower section of the table Sub-Classifications of the Inner Transition Elements 1. Lanthanides Atomic numbers 58 to 71; follow lanthanum 2. Actinides Atomic numbers 90 to 103; follow actinium © 2016 Cengage Learning Periodic Table of Elements © 2016 Cengage Learning  Periodic Table of Elements 3 Categories of Elements Based on Metallic Properties 1. Metals - good conductors (heat, electricity); malleable, ductile, and lustrous; form cations 2. Nonmetals - poor conductors; form anions 3. Metalloids - intermediate between metals and nonmetals © 2016 Cengage Learning Classify each element as Periodic Table of Elements metal, nonmetal, or metalloid. 1. Oganesson Answer: Nonmetal 2. Neptunium Answer: Metal 3. Polonium Answer: Metalloid 4. Iodine Answer: Nonmetal 5. Chromium Answer: Metal © 2016 Cengage Learning 3 6 Common Particles Encountered in Nuclear Reactions  1  In addition to the particles at the table below, protons 1 H ,deuterons  2 1 H   ,and tritons 3 H are commonly encountered in nuclear reactions. 1 © 2016 Cengage Learning 3 7 Practice Exercise 2: Nuclear Decay Equations Alpha Decay 90 Beta Decay Gamma Emission Nuclear Reaction Type of Reaction No. of Protons Lost or Change in Gained by the Parent Mass Number Nucleus Alpha Decay Lost 2 Minus 4 Beta Decay Gained 1 None © 2016 Cengage Learning 3 8 Identifying Radionuclides © 2016 Cengage Learning 3 9 Practice Exercises 3: Identify the radionuclide in each pair and state your reasoning. R n © 2016 Cengage Learning 4 0 HALF LIFE The time it takes for half of the nuclei of a given sample to DECAY OF THORIUM-234 OVER TWO HALF-LIVES THORIUM-234 decay After one half-life has expired, HAS A HALF-LIFE OF 24 DAYS only one-half of the original amount of radionuclide DECAY CURVE remains undecayed FOR ANY RADIONUCLIDE After 2 half-lives only one- quarter (½ of ½) of the original amount of the radionuclide remains undecayed © 2016 Cengage Learning 4 1 RADIOACTIVE DATING Because of their constant decay rates, radioisotopes can be used as nuclear “clocks” Scientists can determine the age of objects that contain radioisotopes Example: Carbon-14 Dating Once an organism dies, it ceases to take in 14C, and the 14C present at death starts to undergo radioactive decay After about 10 half-lives, very little 14C remains, and it is therefore barely measurable 40,000–50,000 years is the current limit of age-dating using 14C © 2016 Cengage Learning 4 2 Uses of Radionuclides A weak radioactive source ionizes the air and sets up a small current If smoke particles enter, the current is reduced, causing an alarm © 2016 Cengage Learning 4 3 Uses of Radionuclides © 2016 Cengage Learning 4 4 Nuclear Reactors – Potential Dangers © 2016 Cengage Learning 4 5 Nuclear Accidents © 2016 Cengage Learning 4 6 Nuclear reactions occur when atoms of one species of chemical element are transformed into atoms of another species by nuclear change. Are you in favor of reviving the Bataan Nuclear Power Plant? Why or why not? EXPANSION/D Fukushima Daiichi Nuclear Power Plant Meltdown, 2011 EEPENING Morong, Bataan (1976) © 2016 Cengage Learning 4 7 UNIFYING/VALUING Meaningful Closure: Do you believe that there are no coincidences in life? Explain your answer. Note: Relate your answer to the lesson and provide a real-life application. © 2016 Cengage Learning