What can be determined from examining the fossil record?

A.

when many life forms became extinct

B.

when many life forms first appeared on Earth

C.

when changes to the diversity of life forms occurred

D.

all of these

Tyrone wants to buy peanut butter that does not contain any hydrogenated oils. What should Tyrone be concerned about?

The element or compounds that are present after a chemical change

The accepted ΔH for a reaction is - 42.3 kJ/mol. A student has performed a lab experiment to determine the enthalpy change of the same reaction. Calculate the percent error Student 1 Exp. ΔH (kJ/mol) Trial 1 - 43.8 Trial 2 - 41.0 Trial 3 - 42.7

What elements are classified as metalloids? And list 3 characteristics of nonmetals

Convert 1.67 x10^24 atoms of carbon to moles of carbon

Identify the spectator ions in the following complete ionic equation. 2k (aq) s2 - (aq) pb2 (aq) 2no-3 (aq) →pbs (s) 2k (aq) 2no-3 (aq) express your answers as ions separated by a comma.

4. A bird left its post and flew in a triangular path. It flew 21 yards south, 72 yards east and 75 yards diagonally to end back at the post. Is it a right triangle?

Condension occurs in the inside of your windows in Winters, why?

How can you use Hess's law to determine a reaction's enthalpy?

7. How much energy in KJ is released when 15.0 g of steam at 100.0 degrees Celsius is condensed and then frozen to ice at 0.0 degrees Celsius?