If 72.5 grams of calcium metal (ca) react with 65.0 grams of oxygen gas (o2) in a synthesis reaction, how many grams of the excess reactant will be left over when the reaction is complete? be sure to write out the balanced equation for this reaction and to show all of your work.

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next

3. how much energy in joules is required to evaporate .0005 kg of liquid ammonia to vapor at the same temperature? 4. how much energy ( in megajoules ) is given up by .75 kg of water at 0c when it freezes to form ice at 0c? 5. explain how heat works between and at critical temperatures?

Uranium can supply energy for the worlds electricity without admitting harmful greenhouse gases which of these statements best describes an outcome of uranium mining