How are elements mixtures and compounds similar? How are they different? Plz hurry

You are given an electron micrograph of a bacterial cell. in the micrograph you can clearly see three thin layers of different densities surrounding the cell. based on the micrograph, you can infer that this cell is and would appear after application of the gram stain procedure. gram-negative / pink gram-positive / purple gram-positive / pink gram-negative / purple