Which of the following is an example of erosion? water freezing inside the cracks of rocks
stalactite and stalagmite formation in caves
plant roots pressing against the sides of rocks
glaciers moving rocks and soil through a valley

Glaciers moving rocks and soil through a valley

Explanation:

The definition of Erosion is "the process of eroding or being eroded by wind, water, or other natural agents". Which in turn means the movement of glaciers is causing erosion on the local valley.

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.