Final answer:
The number of leaves on a tiller varies with the species and growth stage; nitrogen with an atomic number of seven has two electron shells; and the leaf arrangement on a macadamia nut tree is whorled.
Step-by-step explanation:
The number of leaves on a single tiller can vary, but the question does not provide enough context to give A tiller is a stem produced by grasses, and the number of leaves may depend on the species and the stage of growth. Typically, a young tiller will have only a few leaves, while a mature tiller may have more.
Regarding nitrogen, it has an atomic number of seven which suggests it likely has two electron shells. The first shell can hold up to two electrons, while the second shell can hold up to eight. Therefore, nitrogen, with its seven electrons, will have a fully occupied first shell and a second shell with five electrons.
The arrangement of multiple leaves attached to the same node, as observed on the macadamia nut tree, is characterized as whorled leaf arrangement. In this arrangement, three or more leaves grow at a single point or node on the stem, forming a circle around the stem. This is less common than other leaf arrangements like alternate or opposite.