Answer:
Transaction                       Assets            Liabilities        Stockholders' Equity
Issue common stock           Increase               NE                      Increase
Issue preferred stock         Increase               NE                      Increase  Purchase treasury stock     Decrease             NE                       Decrease
Sale of treasury stock         Increase              NE                        Increase  Declare cash dividend            NE                   Increase                   NE
Pay cash dividend               Decrease            Decrease NE
100% stock dividend              NE                        NE                      NE
2-for-1 stock split                    NE                       NE                         NE
When shares are sold or issued, they increase the stockholders equity as people buy these shares. They also increase assets because cash comes into the company when the shares are sold. This is why the Issuing of preference and common stock as well as the sale of Treasury shares had the same effects. 
When cash dividends are declared, they become a liability that is owed to equity holders. 
When these dividends are then paid, they remove the liability but reduce assets as cash is used to pay the dividends. 
100% stock dividend reduces retained earnings but increases equity so stockholders equity does not change.