Which of the following pairs does not share the same empirical formula?

ch2o and c3h6o3
pbcl2 and pbcl4
no2 and n2o4
c3h12 and ch4

According to the tide table below what time of day will the highest tide occur?

Atrain travels 74 kilometers in 3 hours, and then 81 kilometers in 5 hours. what is its average speed?

The famous scientist galileo galilei did several experiments with sloping planes, which he rolled metal balls down so that he could study motion. by changing the slope, he could study how the speed at which the ball rolled was affected. what was the independent variable in galileo's experiment? a. the speed of the ball b. the slope of the plane c. whether the ball moved d. what the ball was made of