According to the general trend, the ionization energy for a group of elements (increases/decreases) proceeding up a group in the periodic table.

Periodic Table:

2 3 4 10 6 3 7 11 Li 6.94 1 IA Na 22.99 19 37 5 Rb K 39.10 al 55 4 87 2 IIA Fr (223) Be 9.01 12 Mg 24.31 Sr 85.47 87.62 20 38 Ca Sc 40.08 44.96 21 56 Cs La Ba 132.91 137.33 138.91 88 3 IIIB 39 Y 88.91 57 89 Atomic number Symbol Atomic mass Ra Ac (226) (227) 4 IVB 22 Ti 47.88 40 Zr 91.22 72 5 VB 23 V 50.94 41 Nb 92.91 73 -H 1.01 6 VIB 58 Ce 140.12 90 Th 232.04 24 Cr 52.00 42 Mo 95.95 74 104 105 Rf Db (261) (262) (263) Sg 106 59 Pr 140.91 91 7 VIIB Hf Ta W Re 178.49 180.95 183.85 186.21 Pa (231) 25 Mn 54.94 43 Tc (99) 75 107 60 Nd 144.24 8 VIII 92 26 Fe Co 55.85 58.93 Os 190.2 44 45 Ru Rh 101.07 102.91 76 9 VIII 61 Pm (147) 27 108 Bh Mt Hs (262) (265) (266) 93 U NP 238.03 (237) 77 Ir 192.22 109 10 VIII 62 Sm 150.36 94 28 Ni 58.69 46 Pd 106.42 78 11 IB 12 IIB 13 IIIA 5 B 10.81 13 Al 26.98 14 15 IVA 6 C 12.01 14 Si 28.09 32 17 16 VA VIA VIIA 8 7 N 14.01 15 P 30.97 79 Pt 195.08 110 Ds 81 82 Au Hg TI Pb 196.97 200.59 204.38 207.2 111 112 113 114 Rg Cn Nh Fl (271) (272) (277) (286) (285) 29 30 31 33 As Ge Se Cu Zn Ga 63.55 65.39 69.72 72.63 74.92 78.97 16.00 16 S 32.07 34 47 51 48 49 50 52 Ag Cd In Sn Sb Te 107.87 112.41 114.82 118.71 121.75 127.60 80 83 Bi 208.98 115 84 Po (209) 9 F 19.00 Md (258) 17 Cl 35.45 35 Br 79.90 53 I 126.90 85 At (210) 117 116 Mc Ts Lv (289) (293) (294) 66 67 70 63 64 65 68 69 Eu Gd Tb Dy Er Tm Yb 151.97 157.25 158.93 162.50 164.93 167.26 168.93 173.04 96 98 99 100 Cf Es Fm (251) (252) (257) 95 101 102 Pu Am (244) (243) Cm (247) 97 Bk (247) 18. VIIIA 2 He 4.00 10 Ne 20.18 18 Ar 39.95 36 Kr 83.80 54 Xe 131.29 86 Rn (222) 118 Og (294) 71 Lu 174.97 103 No Lr (259) (260)