Calculate the energy of a photon with a wavelength of 535 nm.   h = 6.626×-34 J∙s and c = 2.998×108 m∙s–1

Which sample represents a larger mass?

Carbon tetrachloride, CCl4,  is a liquid with the density of 1.59 g/mL and molar mass of 153.8 g.  How many moles are present in a 10.0 mL sample of CCl4?

When a 45.0 g sample of a certain metal at 100.0 °C is dropped into a coffee cup calorimeter containing 100.0 g of water at 25.0 °C, the thermal equilibrium is reached at 37.0 °C.  What is the specific heat of the metal?  The specific heat of H2O(l) is 4.184 J·g–1·°C–1. Assume no heat is lost to the walls of the cup and to the surroundings.

In the structure below octet rule is fulfilled for al atoms but lone electron pairs are not shown. Determine the molecular geometry around the N atom in this molecule.

Consider Lewis structures of carbon monoxide, CO, and carbon dioxide, CO2. Which statement best describe the carbon-oxygen bond in these two?    

If element X has the first three ionization energies of these values:  250, 800, and 3340 kJ·mol–1 , what is the most likely formula for the stable ion of X?

What is the energy effect when 0.50 mol XO and 0.50 mol O2 are allowed to react? 2 XO + O2 –> 2 XO2          ΔH rxn = 120 kJ.   

When selenium forms a stable ion, it ________ electrons to form an ion with a ________ charge.

 Acetone, CH3COCH3, has the molar mass of 58.08 g/mol. What is the mass (in g) of 0.852 mol of acetone?