Office(n.) The place where any kind of business or service for others is transacted; a building, suite of rooms, or room in which public officers or workers in any organization transact business; as, the register's office; a lawyer's office; the doctor's office; the Mayor's office.
The density of mercury (Hg) is 13.534 grams per milliliter. There are 29.5735297 milliliters in a fluid ounce. Therefore, there are 13.534 g/mL * 29.5735 mL/fl oz.
However they are very different worlds. Mercury is over 40 percent larger than the moon, and much more massive and denser than the moon. In fact, it's density is almost the same as Earth's at about 5.4 grams per cubic centimeter as opposed to the moon's 3.3 grams.