Which of the following pairs are about equal in mass?
a. proton and electron
b. electron and neuron
c. proton and neutron
d. nucleus and surrounding electrons

The first element on the periodic table of elements is carbon. a. true b. false

How does concentration affect reaction rate

Which of the following natural processes is most likely to support the formation of an underwater sinkhole? a pollution buildup from deposited minerals b limestone cave collapsing due to changes in sea level c erosion of large amounts of sand moved by ocean waves d oxidation of rock formed by chemical weathering