**Chemical Inhibition and Decontamination: Key Concepts**1. **Chemicals Best at Inhibiting Both Gram-negative and Gram-positive Bacteria** - Selection Options: [Choose]2. **Chemical Least Effective at Inhibiting Both Bacteria** - Selection Options: [Choose]3. **Chemical Which is a Combination of an Alcohol and a Halogen** - Selection Options: - Tincture of Iodine - Soap - Bleach and Iodine - 1:10 Freshly Diluted Bleach4. **Chemical Recommended by CDC for Decontamination of Surfaces Contaminated with Blood Possibly Carrying HIV/Hepatitis B or C Viruses** - Selection Options: [Choose]5. **Chemicals Which are Halogens, Powerful Oxidizing Agents** - Selection Options: [Choose]**Note:** The dropdown menus suggest different chemical options to address each category, with an example highlighted under the combination of alcohol and a halogen. Below are the results of our disc diffusion study using antiseptics and disinfectants. Use the results to answer the following questions:| | 1:10 diluted bleach (BL) | Lab Disinfectant (DIS) | Isopropanol (ISP) | Lab soap (SO) | Lysol (LYS) | Tincture of iodine (T of I) ||------------------|---------------------------|-----------------------|------------------|--------------|-------------|-----------------------------|| **E. coli** | 40 mm | 20 mm | 10 mm | 5 mm | 15 mm | 60 mm || **Bacillus cereus** | 50 mm | 35 mm | 15 mm | 8 mm | 20 mm | 70 mm |- **Chemical(s) best at inhibiting both Gram-negative and Gram-positive bacteria**: [Choose]- **Chemical least effective at inhibiting both bacteria**: [Choose]Explanation:The table summarizes the results of a disc diffusion experiment assessing the effectiveness of various chemicals against two types of bacteria, _E. coli_ (a Gram-negative bacterium) and _Bacillus cereus_ (a Gram-positive bacterium). The measurements, recorded in millimeters, indicate the diameter of the inhibition zones around each chemical, reflecting its effectiveness. Larger numbers signify greater antibacterial activity.

Bacteria are microscopic, unicellular, prokaryotic organisms found in diverse environments. They can be pathogenic in nature. It is necessary to distinguish various kinds of bacteria and also to stain them for observation. The process of gram staining was developed by Hans Christain Gram. On the basis of gram staining bacteria are classified as gram-positive bacteria and gram-negative bacteria. The cell wall of gram-positive bacteria is made up of peptidoglycan and they stain blue after gram staining. The cell wall of gram-negative bacteria is made up of murein and they stain orange after gram staining. Bacteria can be harmful or harmless to humans. It is necessary to eliminate bacteria from the surroundings or the body. Various disinfectants and antiseptics are used to eliminate the bacteria and disinfect various objects.Various disinfectants are used against bacteria. Bleach can be used as a disinfectant. It has sodium hypochlorite which is effective against bacteria as well as fungus and viruses. Lab disinfectant which is mostly ethyl alcohol is widely used as a disinfectant for destroying common bacteria Isopropanol is the most common and widely used disinfectant. It is used in various concentrations but the 70% diluted is preferred the most. The presence of water plays a crucial role in destroying bacteria. lab soap is the common disinfectant used in various research laboratories for cleaning and washing. Lysol is a type of phenol used as a disinfectant. It is actually a 50% solution of cresol. Tincture of iodine is the iodine solution used as antiseptic. It is a halogen and oxidizing agent The antibiotic sensitivity or the effect of the disinfectant on the growth of bacteria can be studied by using the disc diffusion method. The basic principle of disc diffusion is that the disinfectant or the antiseptic diffuses into the medium and the declining concentration gradient is formed, as the distance from the disc increases. Azone of inhibition is formed around the disc indicating the effect of the disinfectant. The greater the zone of inhibition more effective is the drug. Various disinfectants and antiseptics like 1:10 diluted bleach(BL), lab disinfectant (DIS), isopropanol(ISP), lab soap(LS), Lysol(LYS), tincture of iodine(T of I) are tested for their effects E coli that is gram-negative and Bacillus cereus that is gram-positive bacteria. The disc diffusion method is used. On E coli the zone of inhibition of BLwas 40mm, DIS was 20mm, ISPwas 10mm, LS was 5mm, LYS was 15mm, and Tof I was 60mm. On Bacillus cereus the zone of inhibition of BLwas 50mm, DIS was 35mm, ISPwas 15mm, LS was 8mm, LYS was 20mm, and Tof I was 70mm The result shows that the Tincture of iodine is the best in inhibiting both the gram-positive and gram-negative bacteria since it showed the highest zone of inhibition in both the bacteria. The result shows that the soap is the least effective in inhibiting both the gram-positive and gram-negative bacteria since it showed the lowest zone of inhibition in both the bacteria. Isopropyl alcohol is recommended by the CDC to disinfect surfaces contaminated by the blood possibly HIV or Hepatitis B virus Iodine is a halogen and common oxidizing agent