Below is a possible solution to the challenge - Challenge 42 – Split a Sentence Into Words in Different Cells

Enter following formula in B1 and drag to the right and down.

=IFERROR(MID($A1,FIND("@",SUBSTITUTE(" "&$A1&" "," ","@",COLUMNS($A:A))),
FIND("@",SUBSTITUTE(" "&$A1&" "," ","@",COLUMNS($A:B)))-1-
FIND("@",SUBSTITUTE(" "&$A1&" "," ","@",COLUMNS($A:A)))),"")

The workbook containing this solution can be downloaded from Solution - Challenge 42 – Split a Sentence Into Words in Different Cells