Is the youngest part of a rock from the bottom up or from the top to the bottom?

How do scientists tell how old a rock is other than that?

The youngest part of a rock is always on the top as the oldest is on the bottom.

Scientists look at the color and the form of rocks to also determine how old a rock is

Studying rocks are boring so I don’t really find them interesting

In these areas, a high level of leaching takes place. When leaching occurs, nutrients are taken from the soil and not readily replaced. After this occurs over time in humid climates, the soil tends to be depleted and not contain certain nutrients essential for plant life.