In which Era did the first fish appear?

If 20.0g of MgSO4⋅7H2O is thoroughly heated, what mass of anhydrous magnesium sulfate will remain?

Write a balanced equation for the thermal dehydration barium chloride

Which one would be expected to happen? If one of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3).

Solve each problem give your answer to the correct number of significant figures and in scientific notation a. 8.73 meters • 2.22meters b. 8432 meters divided by 12.5 c. 35.2 seconds • 1minute/60seonds

Which of the following reactions have a positive ΔSrxn? Check all that apply. 2A (g) + B (s) - -> 3C (g) 2A (g) + B (g) - -> C (g) A (g) + B (g) - ->C (g) 2A (g) + 2B (g) - ->5C (g)

Which symbols would be included in the noble gas notation for an element that had valence electrons in the 5s subshell? Ar Kr Xe Rn

A sample of sulfur dioxide occupies a volume of 562 mL at 45.° C and 720 kPa. What volume will the sulfur dioxide occupy at STP?

Does a solution have to involve a liquid? Explain your answer

Dog hdgfbxhs dsddssdd

How to prove that NaCl is homogeneous mixture.