For each of the following pairs, identify the sublevel that is filled first. (use lower case letters in your answer) a. 2s or 3s b. 3p or 3s c. 3d or 4s d. 4f or 6s

Complete the sentence. the lower the hydrogen ion concentration, the the ph. higher lower closer to 7 closer to 0

Which formula equation represents the burning of sulfur to produce sulfur dioxide? s(s) + o2(g) 4502(9) 2h2s(s) + 302(g) —> 2h20(0) + 2502(9) 4fes2+1102 —> 2fe2o3 + 8502 2802(g) + o2(9) v205 , 2503(9)

As we move from left to right across the periodic table, what is the general trend? a) atomic radii increase. b) electronegavitiy decreases. c) nuclear shielding increases. d) metallic character decreases.