Complete the following chemical reactions:(a) 3Fe + 4H₂O ------>(b) Ca + H₂O     ------>(c) K + H₂O        ------>

The following chemical reactions are given below:

$ ( a) \ 3Fe\ +\ 4H_{2} O\ \rightarrow \ Fe_{3} O_{4} \ +\ 4H_{2} \uparrow$

$ ( b) \ Ca\ +\ 2H_{2} O\rightarrow \ Ca( OH)_{2} \ +\ H_{2} \uparrow$

$ ( c) \ 2K\ +\ 2H_{2} O\rightarrow \ 2KOH\ +\ H_{2} \uparrow$