Basically just name the first element, then the next followed be "ide"
19. calcium chloride
20. barium fluoride
21. sodium oxide
23. strontium fluoride
24. sodium iodide
25. magnesium oxide
26. lithium fluoride
27. calcium oxide
28. nitrogen phosphide
29. strontium iodide
30. rubidium nitride
If this is not what you mean, let me know!
