Often, the rock layers bookending the mass extinction are noticeably different in their compositions. These changes in the rocks show the effects of environmental disturbances that triggered the mass extinction and sometimes hint at the catastrophic cause of the extinction
I think because each element has its own number of protons and neutrons, giving it its own atomic number and mass (correct me if I’m wrong please)
Answer:
If you are meaning O2^2- ion, well, don’t forget that ions have a charge, that has to be specified when referring to them. It is a polyatomic ion just because it consists of more than one atom, irrespective of the fact that these atoms are of the same element or not. It was given that name because at the early times chemistry was founded as a science, it was found that with respect to other oxygenated substances, peroxides contained more oxygen than expected: Latin prefix per- gives the terms it is attached to the meaning of being increased, enhanced, and similar.
Explanation:
The molar mass of CuCl2 is 134.45 g/mol; therefore, you divide 2.5 g of CuCl2 by 134.45 g of CuCl2 leaving you with 0.019 moles.
I hope this works.
PLEASE GIVE ME A BRAINIEST CROWN.
