1. Circle the letter of each sentence that is true about water's structure. a. Water is made up of atoms bonded to form molecules.
b. Water contains half as many hydrogen atoms as oxygen atoms.
I
c. Water molecules tend to push away from each other.
d. The chemical formula for water is H20.

Heat from earths interior and pressure from overlying rock transform the remains of marine sediments into

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 8 options: the cold balloon expands and rises. the warm balloon shrinks and sinks. the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the warm balloon expands and rises. the cold balloon shrinks and sinks.

Brass gets discoloured in air because of the presence of which of the following gases in air? a. oxygen b. hydrogen sulphide c. carbon dioxide d. nitrogen