Which of the following neutral elements requires the most amount of energy to form a +1 cation?

When g of calcium metal completely reacts with excess water, what is the pressure, in atm, of hydrogen gas that forms when the reaction is performed in a L container at a temperature of °C? Note: Do NOT include any unit symbols in your answer.

Use the provided heats of formation to determine the change in enthalpy for the following reaction, in kJ/mol:  Molecule:  

In which case does a dashed line correctly indicate a hydrogen bond between adjacent molecules?    

What ions would be produced when 1 mol of Al2(Cr2O7)3 is dissolved in water, assuming it is soluble?

How many pi (π) bonds are present in the molecule below?

In which case does a dashed line correctly indicate a hydrogen bond between adjacent molecules?    

Consider the compound etherium (II) bromate, Em(BrO3)2, where etherium, Em, is a made up element with a molar mass of g/mol. What is the mass percent of etherium in this compound? Note: Do NOT enter the % symbol in your answer.

Which of these statements is false regarding properties of atomic orbitals?

Consider the reaction provided below. If you started the reaction with 3.14 g of calcium oxide and g of water, how many grams of calcium hydroxide do you expect to produce, assuming 100% efficiency? You can use the following molar masses: CaO = 56.08 g/mol H2O = 18.02 g/mol Ca(OH)2 = 74.10 g/mol Note: Do NOT include any unit symbols in your answer.