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Introduction to Chemistry. Aristotle (Greece, 4 th Century BC). Philosopher who believed that: There are 4 elements: earth, water, air, fire. Matter is divisible. Democritus (Greece, 4th Century BC). First atomic theory Atom (indivisible).
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Aristotle (Greece, 4th Century BC) Philosopher who believed that: • There are 4 elements: earth, water, air, fire. • Matter is divisible.
Democritus (Greece, 4th Century BC) • First atomic theory • Atom (indivisible).
Alchemists (~300BC-1650 AD)China, India, Arabia, Europe, Egypt • Aiming to: • Change common metals to gold. • Develop medicines. • Developed lab equipment. • Mystical.
Galileo Galilei (Italy 1564 AD) • Father of the scientificmethod (along with the Englishman Francis Bacon 1500’s).
Antoine Lavoisier (France 1743-1794) • Regarded as the Father of Chemistry. • Designed equipment. • Used observations and measurements. • Discovered nitrogen.
Dmitri Mendeléev (Russia, 1834-1907) • First Periodic Table of elements.
Elements • Pure substances that cannot be separated into different substances by ordinary processes • Are the building blocks of matter • 112 elements known today Examples: carbon gold calcium LecturePLUS Timberlake
Symbols of Elements • Use 1 or 2 letter abbreviations • Capitalize the first letter only Examples: C carbon Co cobalt N nitrogen Ca calcium F fluorine Br bromine O oxygen Mg magnesium LecturePLUS Timberlake
Symbols from Latin Names Element Symbol Latin name Copper Cu cuprum Gold Au aurum Lead Pb plumbum Mercury Hg hydrargyrum Potassium K kalium Silver Ag argentum Sodium Na natrium Tin Sn stannum LecturePLUS Timberlake
% Major Elements in the Body O 65.0 % K 0.34 C 18.0 S 0.26 H 10.0 Na 0.14 N 3.0 Cl 0.14 Ca 1.4 Fe 0.004 P 1.0 Zn 0.003 Mg 0.50 Trace Elements As, Cr, Co, Cu, F, I, Mn, Mo, Ni, Se, Si, V LecturePLUS Timberlake
Learning Check Select the correct symbol for each: A. Calcium 1) C 2) Ca 3) CA B. Sulfur 1) S 2) Sl 3) Su C. Iron 1) Ir 2) FE 3) Fe LecturePLUS Timberlake
Solution Select the correct symbol for each: A. Calcium 2) Ca B. Sulfur 1) S C. Iron 3) Fe LecturePLUS Timberlake
Learning Check Select the correct name for each: A. N 1) neon 2) nitrogen 3) nickel B. P 1) potassium 2) phogiston 3) phosphorus C. Ag 1) silver 2) agean 3) gold LecturePLUS Timberlake
Solution Select the correct name for each: A. N 2) nitrogen B. P 3) phosphorus C. Ag 1) silver LecturePLUS Timberlake
Periodic Table The periodic table is an arrangement of the elements according to similarities in their chemical and physical properties. LecturePLUS Timberlake
Physical Properties The characteristics of a substance that can be observed without changing the substance. • Color • Size • Shape • Density • Freezing and Boiling Points • Odor LecturePLUS Timberlake
Using the Periodic Table • Atomic Number • Equal to # protons = # electrons • Periodic Table is arranged by this number • Symbol • “Shorthand” for the element – Note 2nd letter is always lowercase • Atomic Mass Number • Total AVERAGE mass of Protons + Neutrons + Electrons 17 Cl 35.5
Electron Energy Levels • Electrons are arranged in “Shells” around nucleus in predictable locations • Fill “seats” closest to nucleus first (concert – best seats) • “Seats” available • Shell #1 2 electrons • Shell #2 8 electrons • Shell #3 8 electrons • Shell #4 18 electrons • Shell #5 32 electrons • Shell #6 50 electrons • Ex. Carbon has 6 total electrons so… Two electrons on first energy level Four electrons on second energy level Question: Could we fit more electrons on the second energy level if there were more electrons in carbon??
Atomic Structure Total # of protons and electrons (in a neutral atom) 17 protons in nucleus 17 electrons orbiting nucleus 17 Cl Element Name Chlorine 35.5 Total Mass of Nucleus 36 - 17 = 18 neutrons (Round Atomic Mass) Notice: electrons follow energy level rules from previous slide.
Groups of Elements • Vertical columns on the periodic table • Similar physical properties • Similar chemical properties LecturePLUS Timberlake
Groups on the Periodic Table 1 2 3 4 5 6 7 8 LecturePLUS Timberlake
Representative Groups • Group 1 Alkali Metals • Group 2 Alkaline Earth Metals • Group 7 Halogens • Group 8 Noble Gases LecturePLUS Timberlake
Location of Some Groups 1 2 3 4 5 6 7 8 A l m k e a t l a i l s A l k a l i n e H a l o g e n s I G n a e s r e t s LecturePLUS Timberlake
Periods on the Periodic Table • Horizontal rows from Group 1 to Group 8. • Numbered 1, 2, 3, …. • Include representative elements and transition elements LecturePLUS Timberlake
Periods on the Periodic Table 1 2 3 4 5 6 LecturePLUS Timberlake