(1) The element Francium is extremely rare and very little is known about its chemical and physical properties. Use the following data to estimate its density and
ionization energy:
Rb
Cs
Density (g/cm
0.86
Ionization energy (KJ/mol) 419
1.53
403
1.87
375
(i) State the group and period of the periodic table to which the following two
elements belong?
( Xe 6s-45d2
(B) [Ne] 3s 3p

How does a catalyst increase the speed of a reaction? a. the catalyst eliminates the activated complex stage, allowing products to form immediately. b. the catalyst lowers the energy level of the reactants, making it easier for them to react. c. the catalyst makes it easier for the activated complex to form, lowering the activation energy. d. the catalyst raises the energy level of the products, making the reaction finish sooner. reset next