ALE. Atomic Structur Nam HEM K. Marr Tam No. Sctio What is a atom? What is th structur of a atom? Th Modl th structur of a atom (Rfrc: sctios.4 -. i Silbrbrg 5 th d.) Th subatomic articls that chmists ar tyically cocrd with ar th lctro, th roto, ad (to a lssr xtt) th utro. Th followig tabl shows what distiguishs o subatomic articl from aothr: Particl harg Mass (amu * ) Symbol usd i th diagrams blow lctro - 0.00055 roto +.008 utro 0.008 * Th atomic mass uit (amu) is quivalt to.0 0-4 g. Suos w had a VERY owrful microsco/camra that allowd us to tak th followig sashots of atoms. (A sashot is ivolvd bcaus th articls withi th uclus of a atom (do t cofus it with a uclus of a cll!) ar i costat motio as ar th lctros i sac outsid of th uclus. To s what s i th uclus, w hav to zoom i ral clos. Hydrog- H Hydrog- H ALE Atomic Structur Fall 008 Pag of
ALE Atomic Structur Fall 008 Pag of Nitrog-4 Nitrog-5 a Nitrid io (a io of itrog) a Fluorid io (a io of fluori) N 4 N 5 4 N 3- F -
a Magsium io 4 Mg + Th followig thr diagrams ar carbo atoms usig th followig symbols (ot draw to scal) = roto (ositiv charg) = lctro (gativ charg) = utro (o charg) Notic th ty of otatio usd for atoms: Ky Qustios 3 4 ( rotos, utros) ( rotos, utros) ( rotos, 8 utros) 3 4 A Z X = chmical symbol of th lmt Z = atomic umbr A = mass umbr,, ad ar otatios that rrst isotos of carbo. H H 3 H, ad ar otatios that rrst isotos of hydrog. Th art of th atom whr th rotos ad utros ar is calld th uclus. a.) How may rotos ar foud i ach of th followig? X b.) How may utros ar foud i ach of th followig? c.) How may lctros ar foud i ach of th followig? ALE Atomic Structur Fall 008 Pag 3 of
a.) Basd o th Modl, what do all atoms (utral or chargd) of Nitrog hav i commo? b.) Basd o th Modl, what do all atoms (utral or chargd) of Hydrog hav i commo? 3. Look at th Priodic Tabl o ag. What is th sigificac of th umbr (calld th atomic umbr ad rrstd by th lttr Z ) that aars abov th symbol of ach lmt o th riodic tabl. (.g., H for Hydrog ad N for Nitrog)? 4. What do all Arsic (As) atoms hav i commo? 5. Th umbr of what subatomic articl dtrmis th idtity of a atom?. Th lft-had surscrit i th symbol for a atom (.g., th i H) is calld th mass umbr ad is rrstd by th lttr A. What subatomic articl(s) dtrmi(s) th valu of A?. Hydrog-, Hydrog- ad Hydrog-3 ar isotos of th lmt Hydrog. Nitrog-4 ad Nitrog-5 ar isotos of th lmt Nitrog. What subatomic articl distiguishs isotos of th sam lmt from ach othr? 8. If rst, what dos th right-had surscrit i th symbol for a atom (.g., th + i 4 Mg + ) tll th radr? a.) Wh a atom bcoms a io (.g., wh N bcoms N 3- ), which subatomic articl udrgos a chag i umbr i th atom? 4 4 b.) Is that articl gaid or lost? Exlai. c. How is th magitud of th charg o a io dtrmid? ALE Atomic Structur Fall 008 Pag 4 of
Exrciss 0. omlt th tabl blow. Isotoic Symbol Z A # of lctros # of rotos # of utros 5 F 3+ 3 S - 4 8 4 48 50 0 5 8. Writ th isotoic otatio (.g. 4 B ) for ach rrstatio of th followig atoms or ios. a.) Isotoic otatio: b.) Isotoic otatio: c.) Isotoic otatio: - 40 - - + 0 40 + 50 0 8 + 33 0. Draw th atomic rrstatios similar to thos i th rvious qustio for ach of th followig atoms or ios. 0 5 5+ a.) 8 Pb b.) 4 B c.) 33 As ALE Atomic Structur Fall 008 Pag 5 of
3. Ruthrford s gold foil xrimt ivolvs assig a bam of -articls (i.. hlium ucli, H + ) through a vry thi sht of gold. Most of th -articls ass through th gold foil (a vry ds mtal) with littl or o dflctio. Howvr, a fw of th -articls ar obsrvd to b dflctd sigificatly som wr v dflctd back to th sourc! a.) Exlai why most of th -articls ass dirctly through th gold foil with littl to o dflctio. b.) Exlai why oly a vry small fractio of th -articls hav larg dflctio agls. c.) Exlai why som of th -articls ar dflctd back to th sourc. What dos this tll you about th structur of th atom? 4. What is th t charg o vry atom? Exlai why. 5. A oxid io (oxyg io) has a charg. (Us your riodic tabl if cssary) a.) How may rotos dos th oxid io hav? b.) How may lctros dos a oxid io hav? ALE Atomic Structur Fall 008 Pag of
PERIODI TABLE OF THE ELEMENTS A 8A What do all of th lmts that ar shadd hav i commo? H.00 A 3 A 4 A 5A 5 A A H 4.00 3 Li.4 4 B.0 5 B 0.8.0 N 4.00 8 O.00 F.00 0 N 0. 3 Na. Mg 4.30 3B 4B 5B B B 8B 8B 8B B B 3 Al.8 4 Si 8.0 5 P 30.4 S 3.0 l 35.453 8 Ar 3.48 4 K 3.0 0 a 40.08 Sc 44. Ti 4.0 3 V 50.4 4 r 5.00 5 M 54.38 F 55.85 o 58.3 8 Ni 58. u 3.55 30 Z 5.3 3 Ga. 3 G.5 33 As 4. 34 S 8. 35 Br.0 3 Kr 83.80 5 3 Rb 85.4 38 Sr 8. 3 Y 88. 40 Zr. 4 Nb. 4 Mo 5.4 43 Tc (8) 44 Ru 0. 45 Rh 0. 4 Pd 0.4 4 Ag 0.8 48 d.4 4 I 4.8 50 S 8. 5 Sb.5 5 T.0 53 I. 54 X 3. 55 s 3. 5 Ba 3.33 5 La 38. Hf 8.4 3 Ta 80.5 4 W 83.85 5 R 8. Os 0. Ir. 8 Pt 5.08 Au. 80 Hg 00.5 8 Tl 04.38 8 Pb 0. 83 Bi 08.8 84 Po (0) 85 At (0) 8 R () 8 Fr (3) 88 Ra.0 8 Ac.03 04 Uq () 05 U () 0 Uh (3) 0 Us () 08 Uo (5) 0 U () Lathaids 58 40. 5 Pr 40. 0 Nd 44.4 Pm (45) Sm 50.4 3 Eu 5. 4 Gd 5.5 5 Tb 58.3 Dy.50 Ho 4.3 8 Er. Tm 8.3 0 Yb 3.04 Lu 4. Actiids 0 Th 3.04 Pa 3.04 U 38.03 3 N 3.05 4 Pu (44) 5 Am (43) m (4) Bk (4) 8 f (5) Es (5) 00 Fm (5) 0 Md (58) 0 No (5) 03 Lr (0) ALE Atomic Structur Fall 008 Pag of