Alex listed the typical steps of fossil formation. 1) an organism dies. 2) the remains fall to the bottom of the ocean. 3) the soft portions decay, and the hard portions remain. 4) the sediment becomes rock. which statement describes the missing step?

The statement 4.

Explanation:

Alex mentioned all the steps of the formation of fossil, however, he forgot to add a step prior to step 4. The step, which he should incorporate prior to step 4 is that the hard portions of the species get buried within the ocean and then the chemical and physical modifications occurs with the species. After that the sediment formation occurs, which eventually gets transformed into rocks.

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"