Humboldt State University ® Department of Chemistry

Richard A. Paselk

Science 331 - Fall 2004

Section 2

Quiz I Study Guide

Terms (be able to define/describe): Scientific method, observation, hypothesis, experiment, temperature, absolute temperature, density, solid, liquid, gas, element, compound, mixture, pure substance, energy, heat, isotope, proton, electron, neutron, Mass number, Atomic mass, periodicity, ion, metal, non-metal, alkali metal, halogen, noble gas, representative element, diatomic, Periodic Table, ionization, ionic compound, formula. Orbital. Chemical bond, ionic bond, covalent bond. Boiling, solid, boiling point (bp), heat of vaporization/condensation, melting point (mp), heat of melting/solidification, Arrhenius acid/base model, "empirical" acid/base definition, heating/cooling curve.

Atoms and Atomic Structure (you will have a Periodic Table provided for these questions): The mass of one mole of carbon twelve. The mass of one atom of carbon twelve. Be able to fill out tables as we did in class for isotopes (for example: given A & Z find numbers of protons, symbol, etc.). Bohr model for atom. What is wrong with the Bohr model? Geometry (shapes) of s-orbitals for hydrogen. Why do we study hydrogen orbitals? Why not other atoms? Predict the charges of the ions of the representative elements. Explain why they have these charges (stable octets - similar to nearest Noble gas).

Chemical Periodicity (you will have a Periodic Table provided for these questions): General properties of elements as exemplified on Periodic Table (which are most likely to lose electrons? gain them? across a period? within a group?). What charges do ions for groups I & II always have? Ions for Al, Cl, I, O and S? (Remember our model for predicting ionic charges for elements: ion achieves electronic configuration of nearest Noble gas.) Where are metals located on the Periodic Table? non-metals? semi-metals? What are the formulas of the various gaseous elements (e.g. He, Ar, O2, N2)? The halogens (X2)? Which elements occur as liquids at room temperature? Gases? What are allotropes of C? (remember, you can find the answers to these questions by looking at the Dept Periodic Table dispay in the hall) How do ionization energy and atomic radii vary on the Periodic chart. Know trends for these properties, elements with highest and lowest values.

Bonding: Predict the charges of ions of the representative elements. Explain why they have these charges (stable octets). Octet Rule. Valence electrons. Lewis Dot Structures. What does the kernal of a Lewis Structure represent? Be able to write Lewis Structures for atoms, ions and simple compounds of the representative elements. How do you guess whether a compound is likely to be ionic or covalent? (Far apart [left-right] vs. close together on Periodic chart.) Don't forget charges for ions and brackets for negative ions! Steric number. Simplified VSEPR Theory. Electronic shapes (linear, trigonal planar, tetrahedral) vs. molecular shapes (linear, bent, trigonal planar, trigonal pyramidal, tetrahedral). When and why do the various electronic shapes give rise to the different moleculer shapes (electronic shape determined by connecting electron pairs and/or bonding electron clouds, molecular shape determined by conecting nuclei of attached atoms). Be able to predict the shapes of simple molecules using Simplified VSEPR Theory.

Chemical Reactions: Be able to balance simple equations by inspection such as we have done in class. Remember the important considerations of conservation of mass. (see Lecture 7) For chemical equations, conservation of mass means that we must have the same numbers of the same kinds of atoms on both side of the equation.

Be able to predict the products and balance simple fuel oxidation reactions (burning). (e.g. CH4 + 2 O2 -> CO2 + 2 H2O)

Predict the charges of the ions of the elements in Groups IA, IIA, VIA, and VIIA. Explain why they have these charges (stable octets, have outer electron structure of nearest Noble gas).

Acids & Bases: What are acids? Bases? What are the charecters of acids and bases. Hydrogen ion, proton, hydroxide ion.


You will be provided with a Periodic Chart. You may bring a 3x5" card "cheat sheet" (both sides).

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© R A Paselk

Last modified 11 November 2004