First Exam Study Sheet Chem 111 Section 3 Fall 2013--No units other than scientific ones will be used (i.e., no ounces, gallons, or other units not used in scientific research). Students should know all conversion factors between scientific units (1000g/kg, 1000mL/L, 100 cm/m, 1 mL/cm3, etc.).LOOK UP PM NM*pm=10-12 m*nm=10-9m--A periodic table will be provided.--Topics in the book or lectures not mentioned here will not be covered on the exam.1. Definitions of elements, compounds, atoms, and moleculesElements: Substance that has only one kind of atomCompounds: Substance that has more than one kind of atomAtoms: Smallest indivisible unit of an elementMolecules: Group of atoms held together by chemical bonds--Some elements are composed of molecules, some are not2. Conversions between the Celsius and Kelvin temperature scales273 + Celsius= Kelvin3. Definition of density, calculations using densitiesDensity: weight of a certain volume of a substancem/v=d, m/d=v, d*v=m4. The components of atoms, their charges, and their weights (for neutrons and protons) in atomic mass units (not in grams)Protons: positive charge, 1 amu, in nucleusNeutrons: no charge, 1 amu, in nucleusElectrons: negative charge, small weight, in orbit around nucleus5. Description of an atom: locations of the subatomic particlesProtons and neutrons in nucleus of atom, electrons in concentric circles orbiting nucleus.8. Definitions of atomic number and atomic weight (mass number)Atomic number: equal to the number of protons in the nucleusAtomic weight: number of protons and neutrons in the nucleus of an atom9. How to find the numbers of neutrons, protons, and electrons in atoms and in monatomic ionsProtons=atomic numberNeutrons=atomic weight- atomic numberElectrons=protons (unless charge)110. Definition of isotopes, and the use of isotopes' atomic weights and average atomic weights in calculations.Isotope: Atoms that have the same atomic number (Z) but different mass numbers(A)11. Approximate locations (only) in the periodic table of metals and nonmetalsMetals left, nonmetals right12. Groups in the periodic table: how the elements in a group are related.*Same number of valence electrons and similar chemical and physical properties13. Periods (rows) in the periodic table: how the elements in a period are related.*Smooth variations, or trends, in periodic properties, across the row14. Definition of allotropes, why allotropes occur in some elements (atoms are bonded differently and arranged differently in space)Allotropes: forms of the same element that differ in their physical and chemical properties* Atoms are bonded differently and arranged differently in space15. Determining the relative strengths of ionic bonding from the magnitude of the charges on the cations and anions, and from the distances between the cations and anions.The smaller the distance between the ions (smaller radius), the stronger the bond is. When there is 1+ with 2-, or 2+ with 3-, there is a larger attraction than with 1+ and 1-. Larger the charge, greater the attraction. 16. Definition of covalent bonds (two atoms sharing some electrons from their electron clouds)Covalent bonds: two atoms sharing some electrons from their electron clouds17. Definition of molecular and empirical formulas, finding an empirical formula from a molecular formula, finding an empirical formula from the molar ratios of theelements in a compound.Molecular formula: actual ratio of elements in a compoundEmpirical formula: simplest ratio of elements in a compound18. Determination of empirical formulas from percent composition of compounds. Determination of molecular formulas from empirical formulas.19. Definition of cations and anions, how atoms become cations and anions (lose or gain electrons), finding the formulas of ionic compounds by balancing the charges oftheir cations and anions.Ions: is an atom with an unequal number of protons and electrons;Cations: When an atom carries more protons than electrons, it carries an overall positive chargeAnions: An atom with more electrons than protons has an overall negative charge220. How to find the number of valence (outermost) electrons of atoms from their positions in the periodic table (Group number)21. How to find the characteristic, or most common, charge of an ion from the element's position in the periodic table. Why this can be done * Electrons are located in concentric shells around the nucleus, which are most stable when filled with eight electrons each, the only exception being the first shell whichis filled with two.22. Definition of an acid and a base (not their names or examples of them). Why hydrogen atoms bonded to some elements are acidic, and hydrogen atoms bonded todifferent elements are not.Acid: loses a proton in water HA H+ + A-*H has to be bonded to a very EN element (halogens or something with a lot of O)Base: forms OH- when dissolved in water. 23. Definition of an organic, or carboxylic, acid.Organic/ carboxylic acid: all have C-O--OH group where the H from OH is the source of the proton.24. Carbonic acid: formula, how it is formed in water, the speed of its formation, thereason the amount of it is increasing in the oceans and why this is a problem (see lecture materials).H2CO3, forms slowly, CO2 maybe it’s a problem since it’s making the ocean more acidic.25. Names, formulas, and charges, of important polyatomic ions (see Ions list on Moodle page) 26. Definition of electronegativity (see lecture materials)27. How electronegativity varies across rows and down Groups in the periodic tableElectronegativity: ability of an atom to attract electrons to itself.Top right is most EN, bottom left is least EN.28. How to determine whether bonds between atoms are ionic or covalent, using electronegativity. How to determine which bonds between different atoms are more ionic or more covalent, using electronegativity (lecture materials)If EN of A>>B=ionic bondIf EN of A>B= polar bond (partially –A and partially –B)If EN of A =B=nonpolar  covalent bond (occurs in cases with the same element bonded to itself or C—H To determine whether the EN is greater than, less than, or equal to another element, look at it’s position on the Periodic table.29. Definition and value of Avogadro's number; definition of a mole (number of atoms of any element whose weight in grams is equal to the element's atomic weightin amu)Avogadro’s number: 6.022x1023 , amount of particles in one moleMole: number of atoms of any