Compared to the bedrock layers above and below the rock ledge shown at the waterfall, the characteristic that is primarily responsible for the existence of the rock ledge is its greater
1.
resistance to weathering
2.
abundance of fossils
3.
thickness
4.
age

The correct answer is option 1, that is, resistance to weathering.

Explanation:

After examining the picture of the waterfall, the feature, which is mainly accountable for the presence of the rock ledge is its greater resistance to weathering. Some kinds of rocks are very resistant to weathering. The igneous rocks, mainly the intrusive rocks like granite, weather gradually as it is tough for water to get inside them. The rocks behave distinctly to weathering because of the differences in the structure of mineral and its content.

chemical properties are the characteristic of matter which can only be observed by changing the chemical identity of a sample like flammability reactivity and toxicity.