Water is H2O so that's Hydrogen and Oxygen.
The awnsers would be D for the first one and A for the second. Let me know if you want an explanation.
Use Absolute Mag™ PEG Coated Iron Oxide Nanoparticles, 20 nm for fast, easy, and consistent DNA/RNA Purification, Antibody/Protein Purification, Cell Isolation. https://www.cd-bioparticles.com/p/Absolute-Mag%E2%84%A2-PEG-Coated-Iron-Oxide-Nanoparticles-20-nm_20_197_197_4997.html
