15.What is one problem that must be overcome before nuclear fusion reactions that produce energy on our planet are a reality? a. Scientists must determine how to control the reaction
b. A company must first apply for a patent
c. Cars have to be redesigned
d. There is not enough open space available in the United States

If equal masses of the listed metals were collected , which would have a greatest volume ? a. aluminum 2.70,b.zinc7.14,c.copper 8.92,d.lead 11.34

Which position represents spring in the southern hemisphere? a) b) c) d)

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