Question

how can you tell if a rock is sedimentary? again, thinking about how rocks form can help you. look for particles, or sediment, in the rock—like sand, pebbles or shells—that might be stuck together. sedimentary rocks tend to be softer than the other rock types. they also are much more likely to contain fossils. some sedimentary rocks contain stripes due to the layers of sediment that form them. the red stone of sedona, arizona, are striped in this way. those rocks are sandstone, a sedimentary rock.
which of the following would be a clue that a rock is sedimentary?
choose one option
a no fossils or layers can be seen.
b there are small clear, hard crystals visible.
c the rock crumbles easily in your hand.
d there are ribbon - like bands of minerals.

Explanation:

• Option A: The text says sedimentary rocks are more likely to have fossils and some have layers, so no fossils/layers is not a clue. Eliminate A.
• Option B: Sedimentary rocks are described as softer, so hard crystals don't fit. Eliminate B.
• Option C: The text states sedimentary rocks tend to be softer, so crumbling easily (a sign of softness) is a clue.
• Option D: The text mentions stripes from sediment layers, not ribbon - like bands of minerals. Eliminate D.

Answer:

C. The rock crumbles easily in your hand.