Using hydrogen in his experiments Bohr showed that an electron spins around the atom nuclei at a specific/discrete radii (orbital levels). Electrons at every orbital level spin at a discrete angular momentum and energy. When the electron moves one orbital level down, it releases a photon of energy specific to the jump (that is, of a particular spectrum that is unique to the atom). When the electron goes up an orbital level, energy (of a specific spectrum) is absorbed. This emission and absorption spectrum varies across atoms and is calculated as (delta)E = hf where;
E = energy
h = Planck's constant
f = frequency
I believe that organ is the brain...
I believe the correct answer among the choices listed above is option B. A gland secretes enzymes through a duct onto the surface of a body part is a salivary gland. It is under the classification of exocrine glands. Hope this answers the question.
Answer:
They remain in an environment,even as more competitive species arrive
Explanation:
Pioneer species, in ecological succession, are the first set of organisms to colonize a bare area of land or a disturbed area of land. Pioneer species include lichens, grasses, fungi etc.
Pioneer species have unique characteristics that distinguishes them from every other species of organism. These include:
- They facilitate environmental change, making an environment more habitable for other species.
- They tolerate a wide range of environmental conditions.
- They are capable of colonizing a barren environment, as in primary succession.
However, pioneer species do not remain in an environment, even as more competitive species arrive. They rather give way for new species to emerge and dominate.
