The homologous structures and the analogous structures of different species.
Answer: An igneous rock that cools rapidly is made of really small mineral crystals.
Explanation:
The layers inside the earth are hot enough to melt a rock. The liquid or molten rock is known as magma.
When a molten rock cools and solidifies, it results in the formation of an igneous rock.
The slow cooling of magma will result in the formation of an igneous rock with large crystals. Whereas, rapid cooling of lava will result in the formation of an igneous rock with small crystals.
Thus, it can be concluded that an igneous rock that cools rapidly is made of really small mineral crystals.
Oxygen for complete combustion
Moles = n/v where n is the moles of solute and v being the liters of solution.
We can put in the information provided to find the molarity.
Moles = .45/3.0 = .15
So we now know that the molarity of that solution is .15!
I hope I helped you :). Make sure to memorize that formula because it's not that hard as long as you know what to plug in.