Why are scientists unable to date most sedimentary rock layers?

carbon decays

Explanation:

they use radioactive carbon but with how old it is it starts to decay

Sedimentary rocks can be dated using radioactive carbon, but because carbon decays relatively quickly, this only works for rocks younger than about 50 thousand years. So in order to date most older fossils, scientists look for layers of igneous rock or volcanic ash above and below the fossil.

Explanation:

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i wish i could with all of them i can barley see the first one so here's the answer to the first one b