Which of the following elements is likely to form a ionic bond with potassium a. ci b. au c. li d. ca

 The element  that  is  likely  to form a ionic  bond  with potassium is  Cl  (answer A)

Explanation

Ionic   bond  -  is a  bond formed  when  a  metal  and  a  non metal react.

Metal loses  electron ( donate  electrons)  while  non metal   gains  electrons  ( accept  electrons)  to form  ionic  bond.

potassium  is a metal  while Chlorine(Cl)  is a non  metal.  They  react  to form an ionic  bond   by potassium  donating  1 electron  while  chlorine accept 1 electron.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

the question isn't complete here so i can't right an answer '_'