The atomic number of krypton (kr) is 36, and its mass number is 84. how many neutrons does it have?

How many liters of oxygen gas, at standardtemperature and pressure, will react with 35.8 grams ofiron metal? 4 fe (s) + 3 o2 (g) → 2 fe2o3 (s)

Pl what kind of reaction is this? nahco3 + h2o → co2 + naoh + h2o -composition -decomposition -single replacement -double replacement im leaning more toward single replacement. if im wrong can you explain whyy?

For part 1, describe the changes in the colors of the well, if any, as you go from well 1 to well 9—that is, as you go from the well with the least copper(ii) nitrate to the well with the most copper(ii) nitrate. which wells had the most distinct precipitate? for part 2, describe the changes in the colors of the well, if any, as you go from well 1 to well 9—that is, as you go from the well with the least iron(ii) sulfate to the well with the most iron(ii) sulfate. which wells had the most distinct precipitate? for part 3, describe the changes in the colors of the well, if any, as you go from well 1 to well 9—that is, as you go from the well with the least iron(iii) nitrate to the well with the most iron(iii) nitrate. which wells had the most distinct precipitate?