Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25General Chemistry Topic 2:Elements, Atoms, and the Periodic TableAll images in these slides are in the public domain.Objectives: By the end of this topic, you should: 1.Be able to define the terms of element, atom, nucleus, electron cloud, isotopes ( and  particles, -rays), ions (anions and cations), atomic number, and atomic mass. 2. Understand the structure of atoms, including protons, neutrons, and electrons, and be able to determine the number of protons, neutrons and electrons in any atom. 3. Know a little bit about the development of atomic theory. 4. Understand the basic concepts of the periodic table, including periods, groups (families), metals, nonmetals, and metalloids.  5. Be able to use the periodic table to obtain information about the chemical properties of an element.  6. Be familiar with elements important in biological systems (first 20 in the periodic table)  7. Understand the relationship between the electron configuration of an element and its position in the periodic table. 8. Understand the concept of valence electrons and the octet rule and be able to use it to predict the charge of common anions and cations. Suggested reading: Denniston et al., Chapter 2, pp. 43-48, 57-61, 69-73 (pp. 43-48, 57-61, 69-75), Chapter 9, pp. 301-308 (298-305)Homework problems: 2.21 (2.23), 2.27 (2.27), 2.34 (2.34), 2.35 (2.35), 2.67-2.72 (2.67-2.72), 2.81 (2.81), 2.107 (2.107), 2.111 (2.111), 2.112 (2.112) 9.19 (9.19), 9.24 (9.24)Body system of organismOrganTissueCellOrganellesMacromoleculesmoleculesAtoms12345667Basic Hierarchy of LifeLife at the molecular level consists of thousands of different biomolecules and several thousand complexes and highly integrated chemical reactions. These reactions define life.We will try to understand the basic chemical and biological processes responsible for life, and how they are altered in abnormal states.Out of the 90 naturally occurring elements, 30 or so are essential for life. Most have relatively low atomic numbers – so-called “light” elements.Four elements, hydrogen, oxygen, nitrogen, and carbon, account for ~99% of the atoms of most cells.Chemistry of life – A basic primerWe are mostly H, O, N, and C >99% of atoms >88% of mass l—H —O— —N —C— l——Carbon (C) is great! Makes 1, 2, 3, or 4 bondswith other atoms or with itself; almost anything possible!Although relatively stable, C-C bonds can be made and broken rather easily – this is good.lightest elements that make: 1 2 3 4 bondsLife is “carbon-based” – why we need some “organic” chemistryBut first we need some “general” chemistry foundations.Basic Chemistry of lifeAn element is a substance whose atoms all have identical nuclear charges and electron configurations.An atom is the smallest representative sample of an element. Atoms are composed of three subatomic particles: Mass* Charge SymbolProton 1 +1 p+ or pNeutron 1 0 nElectron 0.0005 -1 e-*For elements and atoms, we use atomic mass units (amu) – mass of an H atom, 1.661 x 10-24 gElements and AtomsAtoms are mostly empty space (Lord Rutherford), withessentially all mass in an extremely dense central core – the nucleus –which contains protons and neutrons. Electrons move about theatom in a diffuse and largely empty “cloud”.If an atom were the size of Kenan Stadium, the nucleus would be aboutthe size of a golf ball placed at the 50-yard line.Ernest Rutherford(1871-1937)Atomic number = charge of an atom = # of protons (# of+ charges). Atomic number defines the elementAtomic mass (atomic weight) = # of protons + # of neutronsAtoms are electrically neutral, so # of electrons = # of protons Chemical properties of atoms determined by electron configurations.Atomic symbolsH11atomic massatomic numbersymbol of elementp+e-Hydrogen atom6p+6n0 6e-Carbon atomAtomic number = 1Atomic mass = 1Atomic number = 6Atomic mass = 12H11C12 6Elements and AtomsIon: an atom or group of atoms that has an electrical charge because of loss or gain of electrons.11p+11n0 11e-Sodium atom11p+11n0 10e-Sodium ion (Na+)e-17p+18n0 17e-Chlorine atom17p+18n0 18e-Chloride ion (Cl-)e-Cation(+)Anion(-)IonsNaCla “salt”(coming soon)There are 117 elements known. 92 are naturally occurring; the rest have been prepared using high-energy devices. More will likely be made.Each element has a shorthand symbol consisting of one or two letters (first always capitalized; second, if present, always lower case). Some recent synthetic elements have 3 letters.You should know the names and symbols of the first 20 elements, as well as those listed below:Al aluminum Ag Silver Au Gold Ba BariumBr Bromine Ca Calcium Cu Copper Fe IronHg Mercury I Iodine Mn Manganese Pb LeadPt Platinum Zn ZincAtomic SymbolsIsotopes are different atoms of an element; they have the same number of protons and electrons, but different numbers of neutrons.Isotopes have the same atomic number, but different atomic masses (weights).The “relative” atomic mass of an element is the weighted average of all naturally occurring isotopes of that element.IsotopesOther carbon isotopes exist, but in quantities so small that they can be omitted for this example.Write the completeatomic symbols forthe 3 isotopes of hydrogenIsotopes of Carbon Carbon-12 Carbon-13 Carbon-14Isotopes of HydrogenHydrogen - 1 proton, no neutron, 1 electronDeuterium - 1 proton, 1 neutron, 1 electronTritium - 1 proton, 2 neutrons, 1 electronDraw the atomic structures (p+, n, e-) and write the complete atomic symbolsfor the 3 isotopes of carbonHomeworkSome isotopes of some elements are radioactive (radionuclides), their nuclei are unstable and emit “radiation” to become stable.There are 3 types of natural radiation (plus some unnatural ones)Some common radionuclides: 3H (tritium) 14C 32P 131I 60Co3H, 14C, and 32P all decay by -particle emission. Homework: Write the complete atomic symbols for the atom remaining after radioactive decay of 3H, 14C, and 32P.You will need the Periodic Table (coming soon).RadioactivityType Symbol Composition Mass ChargeAlpha  Helium nucleus 4 +2Beta 