The image above shows the nucleus of a nitrogen atom. how can the atomic number of nitrogen be determined?
a. count the humber of neutrons
b. count the number of protons
c. add the number of protons and neutrons
d. count the number of electrons

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