19. Which atom in a water molecule has the greatest electronegativity?
a. one of the hydrogen atoms
b. both hydrogen atoms
c. the oxygen atom
d. There is no difference in the electronegativities of the atoms in a water molecule.

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size

What is the approximate mass of 25 cm3 of silver, if the density is 10.5 g/cm3? a. 0.42 g b. 2.4 g c. 42 g d. 260 g

Which molecules are more strongly attracted to one another -c3h8o molecules that make up liquid rubbing alcohol or ch4 molecules that make up methane gas