Which of the following statements is NOT true about isotopes of the same element?

1. They always have different atomic
weights.

2. They always have different numbers of
protons.

3. They always have the same atomic number.

4. They always have different numbers of neutrons.

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

Magnesium is the limiting reactant in this experiment. calculate the theoretical yield of mgo for each trial. trial 1: trial 2: data mass of empty crucible with lid trial 1: 26.688 trial 2: 26.681 mass of mg metal, crucible, and lid trial 1: 26.994 trial: 2 26.985 mass of mgo, crucible, and lid trial 1: 27.188 trial 2: 27.180

Which compound should undergo substitution of the bromine by phenolate anion? draw the structure of the organic product?