How does vegetation allow greater infiltration?

Vegetation allows for greater infiltration by anchoring soil and keeping it from drying into a hard barren surface through protection from direct sun rays. When the soil is soft, infiltration is greatly enhanced.

Living and decaying roots  create a network of well connected channels in the soil called macro pores. Flow through these macro pores can be several hundred times faster than through the soil matrix.

Leaf litter produces humus. Soil structure is improved as soil particles are cemented together by humus and sugars excreted from roots.  The improved soil structure permits increased infiltration.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.