The core. Because if you look at a Avocado and the model of the earth the core looks similar.
Answer:
1 atom of zirconium
Explanation:
Zirconium sulfide or zirconium disulphide can be written as ZrS2.
Because it is a pure substance, and it will not change because it has nothing mixed with it. When things get mixed, amounts vary, but it's on its own so everything stays the same.
(2) is the only correct answer. (1) 5 grams of H2 is 2.5 mols of this gas, which would result at STP 22.4 * 2.5 Liters (according to Avogadro's law). 5 moles of O2 would result in 5 * 22.4 Liters, and (4) 5 * 10^23 molecules of CO2 (which is what I assume you meant) would be 5 mols, which would result in 5* 22.4 Liters.
(2) is your answer
1. Tilt
2. Revolution - The Earth revolves around the Sun.
3. The North pole always point in the same direction.
Hope it helps.