What do these layers and their fossils suggest about Earth's history? ОА.
Lifeforms on Earth have been the same over time.
ОВ.
No lifeforms were present when these layers formed.
OC. Only one kind of lifeform lived where these layers formed.
OD
There have been changes in Earth's lifeforms over time.

13. calculate the initial concentration (before precipitation) of carbonate ions after the addition of each 0.05 ml of solution b to the 1.00 l beaker of solution a. divide the work among group members and write the answers in the table in model 3. assume the volume change as solution b is added is negligible. 14. notice the initial concentrations of zn2+ - and cu2+ in the table in model 3. a. explain how these were obtained from the data in model 2. b. as solution b is added and precipitates form, do these initial concentrations change? 15. use the data in model 2 to indicate the presence of precipitate (either znco3 or cuco3) after each 0.05 ml addition of solution b in model 3. 16. use the initial concentrations of carbonate ions and zinc ions to calculate the reaction quotient, qsp for the zinc carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3. 17. use the initial concentrations of carbonate ion and copper(ii) ions to calculate the qsp for the copper(ii) carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3.

Ase your answer to this question on the information below.hydrocarbons and fissionable nuclei are among the sources used for the production of energy in the united states. a chemical reaction produces much less energy than a nuclear reaction per mole of reactant.the balanced chemical equation below represents the reaction of one molecule of a hydrocarbon with two molecules of oxygen.chemical equation: ch4 + 2o2 → co2 + 2h2o + 1.48 × 10−18 jthe nuclear equation below represents one of the many possible reactions for one fissionable nucleus. in this equation, x represents a missing product.nuclear equation: write an isotopic notation for the missing product represented by x in the nuclear equation.

Chemical kinetics what was the rate of reaction in trial 3? choose the closest answer.