Select the examples in which the names do not correctly match the formulas of the compounds indicated. I PF5 potassium pentafluoride II N2O4 dinitrogen(IV) oxide III XeO4 xenon tetroxide IV Cl2O5 dichlorine pentoxide

Which compound is not a hydrocarbon?

Which of the following have opposite electric charges?

Which element exists as a diatomic molecule in the free state?

Methane gas (CH4) reacts with oxygen gas (O2) according to the equation below. CH4 + 2O2 → CO2 + 2H2O +energy This reaction releases 890 kJ of energy for each mole of methane gas that is consumed.  Which of the following statements best describes this reaction?

In a sealed bottle that is half full of water, equilibrium will be reached when water molecules

The graph below shows the temperature changes occurring in two hot packs that are made from different materials. The same amounts of water and CaCl2 were used to make each pack. Which of the following inferences is supported by the graph?  

The development of extensive writing systems came before and led to the development of the Neolithic Revolution. 

In the Neolithic era, humans were first developing widespread agriculture and organizing into permanent villages with much greater populations of people than ever before.

Plants and animals were first domesticated as a result of the development of complex social classes and the surplus of time and energy associated with the development of agriculture.