2

• Lead has the most stable isotopes among the options provided
• Toothpaste


  Used for oral hygiene to remove plaque and bacteria, freshen breath, and leave the mouth with a clean feeling
• The property of matter being demonstrated is volume
• Milk of magnesia

  Chemical name is Magnesium hydroxide
• Water is always called by its common name
• Aspirin

  Chemical formula is C9H8O4
• Table salt

  Chemical formula is NaCl
• Boiling Point


  Most useful for Sarah to determine if the liquid is a pure substance or a mixture
• Marsh Gas


  Important source of hydrogen and other organic chemicals used in the manufacture of ammonia for fertilizers and explosives
• Carbon-12 and Carbon-14

  Isotopic pair used in radiometric dating of ancient organic materials
• Quartz


  Used in glassmaking and in the petroleum industry
• Galena


  Most important ore of lead, with most lead used for batteries
• Homogeneous mixture

  Sample consisting of two or more substances evenly distributed throughout
• Uranium-235


  Commonly used in nuclear reactors for power generation
• Chlorhexidine digluconate


  Commonly known as mouthwash
• The pen with ink similar to the pen used to write the note belongs to Michelle
• Michelle has the pen with ink that has the most number of pigments
• Sam has the pen with ink containing only one type of pigment
• Andrei's pen has the ink with pigments that spread out the most
• Kate could be the possible one making the wrong act
• Iron has the most stable isotopes among the elements listed
• Technetium-99m


  Commonly used in medical imaging
• Decantation


  Separating a liquid from a solid by gently pouring off the liquid
• Household bleach

  Chemical name is sodium hypochlorite
• Fractional Distillation is the possible separation technique used if miscible liquids have a significant difference in boiling points generally around 70°C