A sample of hydrogen sulfide has a mass of 73.00 g. Calculate the number of hydrogen sulfide molecules in the sample.

One or more substances changing into one or more substances is an example of a

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

Light waves can move through , but they travel fastest when they move through a(n) .