What best describes index fossils?

Organisms that existed over a limited period

Organisms whose age is hard to detect

Fossils that are used in radioactive dating

Fossils of the most ancient organisms

The answer is letter c

Hbr dissociates to form h+ and br-ca(oh)2 dissociates to form ca2+ and 2oh-the h+ and oh- react to form waterassuming the reactants are dissolved in water, the net reaction is h+ + oh- —> h2oif you’re asked to show all components of the reaction, the complete reaction is 2hbr + ca(oh)2 —> cabr2 + 2h2o