A.
Explanation:
Pioneer plants are to plants species that appear first in virgin land – such an after a volcanic eruption. They are mainly lower plants such as lichen, fungi, and noses. These species can grow on rocks and break them down over time to form soil. This is due to the fact that the plants have very shallow roots that can even grow in the small crevices of rocks and can draw water from the atmosphere – moisture. This releases the nutrients in the rocks and makes them available to higher plants that have deeper roots. The ecology of the region will ultimately be succeeded by a climax community over time, mainly dominated by tree species.
The alkaline earth metals (the second group) because their ion charge is +2
Ans: As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit will <u>increase.</u>
The energy (E) is related to the frequency (ν) by the following equation:
E = hν
where h = planck's constant
The change in energy i between levels is:
ΔΕ = h(Δν) -----(1)
Based on the above equation, as the changes in energy levels increase, the frequency of emitted radiation will also increase.
Yes molecules are tightly together. Hope this helps
