Which topic would you most like to review? Shape, polarity, Lewis structures, intermolecular forces Periodic trends, electron configuration, bonding Atomic structure, history Energy, exo/endothermic All, I know nothing.

Exam #3, etc. Tonight, April 25, 7:00-8:30pm (Conflict: 5:00-6:30pm, 335 Mechanical Engineering Building) No calculators allowed Regular exam room locations on website Bring your ID NO discussion tomorrow Graded exams back in Lab on Monday – Scores posted tomorrow evening Tuesday’s lecture – Final Exam tips/review and Demo Review Day (bring your i-clicker) It will be rockin’!!!!  Last pre-lecture assignment is due Tuesday 8 am, last i- clicker points day is Tuesday

Home Energy Consider the following processes to answer the next question. The system is underlined. I. A match burns after it is struck against a matchbox. II. A pot of liquid water boils on the stove. III. A banana freezes after it is submerged in liquid nitrogen. IV. Solid CO2 (dry ice) sublimes into gaseous CO2. Which of the following are exothermic processes? a) I, II b) I, III c) II, IV d) I only e) IV only

Energy Home Which of the following statements about energy is false?   A reaction cannot be exothermic overall if activation energy is required. A system is the most stable when it is at its lowest energy state. Energy can be defined as whatever is required to oppose a natural tendency. Energy transferred into a system can also be transferred out of the system. An atom in an excited state can return to its ground state by releasing visible light.

Home Periodic Trends Which atom or ion has the lowest ionization energy? a) O2+ b) O+ c) O d) O– e) O2–

Home Periodic Trends The electron configuration 1s22s22p63s23p64s23d104p6 is the correct electron configuration for the most stable form of which ion?   a) the krypton ion b) the strontium ion c) the calcium ion d) the cesium ion e) the xenon ion

Periodic Trends Choose the bond that is the most polar. a) N–N b) C–O Home Periodic Trends Choose the bond that is the most polar.   a) N–N b) C–O c) P–S d) Sr–O e) Fe–P

Home Periodic Trends Rank the following from smallest to largest atomic radius. a) O, Zn, Ca, Ba b) O, Ca, Zn, Ba c) Ba, Ca, Zn, O d) O, Zn, Ba, Ca e) Ca, Ba, Zn, O

Atomic Structure & History Home Atomic Structure & History Which scientist is still credited today for determining how an electron moves around the nucleus of an atom?   Ernest Rutherford J.J. Thomson John Dalton Niels Bohr No scientist is credited for this discovery because we do not know exactly how electrons travel in an atom.

Atomic Structure & History Home Atomic Structure & History When an electron is excited in an atom or ion the electron moves further from the nucleus. only specific quantities of energy are released in order for the electron to return to its ground state. white light is never observed when the electron returns to its ground state. the electron is only excited to certain energy levels. All of the above statements are true when an electron is excited.

Home Molecular Structure Draw the Lewis structures for the following compounds below to assist you in answering the next three questions. CBr2H2 BH3 XeCl4 SF4 HCl How many of the compounds above are nonpolar? a) 1 b) 2 c) 3 d) 4 e) 5

Home Molecular Structure Use the compounds below to assist you in answering the next two questions. CBr2H2 BH3 XeCl4 SF4 HCl Which compound has bond angles of 109.5˚ around the central atom? a) CBr2H2 b) BH3 c) XeCl4 d) SF4 e) HCl

Home Molecular Structure Use the Lewis structures for the compounds below to answer this question. CBr2H2 BH3 XeCl4 SF4 HCl Which compound has a see-saw shape? a) CBr2H2 b) BH3 c) XeCl4 d) SF4 e) HCl

Home Molecular Structure Which compound below has the highest boiling point? a) CO b) NH3 c) CO2 d) CH4 e) At least two of the above compounds have equally high boiling points.

Atomic Structure & History Home Atomic Structure & History Which of the following statements is/are true? I. John Dalton provided the first experimental support for the atom. II. Ernest Rutherford proved the existence of a nucleus by shooting positively-charged particles at a thin gold-foil sheet. III. J.J. Thompson proved that electrons travel in elliptical orbits around the nucleus. IV. Energy in an atom is quantized, therefore when electrons fall to their ground state, white light can be observed. a) I, II b) I, III c) I, II, III d) II, IV e) All of the above statements (I – IV) are correct.

Home Energy Liquid water turns to ice. Is this process endothermic or exothermic? Choose the best answer. endothermic; The water absorbed heat and got colder, therefore forming ice. endothermic; Energy in the form of heat was given off by the water to become colder and form ice. exothermic; The water released energy, slowing the water molecules down to form solid ice. exothermic; Heat was absorbed by the water, moving its molecules faster to condense on an object and form ice. neither endothermic nor exothermic; There was no energy transfer in or out of the water to form ice.

Home Periodic Trends Which has a smaller atomic radius, an atom of fluorine or an atom of lithium? Choose the best answer. They are the same size because their electrons are contained in the same principle energy level. An atom of lithium is smaller than an atom of fluorine because lithium has fewer protons. An atom of lithium is smaller than an atom of fluorine because as you add electrons going across a row, the electron shells get further and further from the nucleus. An atom of fluorine is smaller than an atom of lithium because with more protons the electrons are pulled closer to the nucleus. An atom of fluorine is smaller than an atom of lithium because fluorine has a high ionization energy and will not lose electrons as easily as lithium.