What is one major difference between volcanic activity on earth and volcanic activity on mars, venus, and the moon? explain.

While the Moon and Mercury have relatively small volcanoes, those on Venus, Earth and Mars are large and numerous.  Earth's volcanoes are still active and Venus' may be, but scientists debate whether Mars' volcanic activity has finished.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.