Why are anionic nutrients generally mobile in soils, and thus easily leached, while cationic nutrients are relatively immobile?

Why did rutherford say that bombarding atoms with particles was like "playing with marbles" what

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction.

What is the ecological role of food chains and food webs