Write the formula equation for potassium + iodine -> potassium iodide and balance the equation

2 K + I2 }  2 KI 
Iodine is diatomic so when it is "by itself" it has to be bonded to another one of its atoms so it has a subscript of 2 on the left and to balance the other side you put a 2 before potassium iodide and then you have to put a 2 in front of the potassium on the left side as well.

Ch4 is nonpolar and insoluble in water. since all of the hydrogen atoms are evenly spread around the carbon atom even through the c h bond is polar all the poles cancel each other out.