Answer:
The s-, p-, and d-block elements of the periodic table are arranged into 18 numbered columns, or groups. The elements in each group have the same number of valence electrons. As a result, elements in the same group often display similar properties and reactivity.
Explanation:
I would say that La Nina is responsible for dry conditions in California and typically it is the year after La Nina that the dryness turns often to severe drought. Drought can be bad for agriculture requiring a lot more irrigation and posing a drain on water resources which decrease also during a drought,
Answer:
Some lichen symbionts can survive independently on bare rocks in the absence of any external source of organic matter due to the ability of the phototrophic partner to fix CO2 from the air, and <u>nitrogen fixation by the cyanobacterial partner.</u>
Explanation:
Lichen are organisms formed from the symbiotic association of a fungus with an organism capable of photosynthesis, be it an algae, a cyanobacterium, or both.
The fungus depends entirely on the photosynthetic organism in its metabolism of carbohydrates, receiving sugars or saccharine alcohols from it. For its part, the algae depends, for its metabolism, on the water and the mineral substances that the fungus provides it, at the same time that it is also protected by it from too high light intensities.
Answer:
A. np and nf
Explanation:
The electron distribution into energy levels or sublevels of atoms can be shown in their sublevel notations. This shows the sequence of filling electrons into the orbitals of the sublevels as guided by some principles such as the Aufbau Principle, Pauli Exclusion Principle, Hund's Rule of Maximum Multiplicity e.t.c
The maximum number of electrons in the orbitals of sublevels are two for s-sublevel(one orbital), six for p-level (three orbitals), ten for d-sublevel (five orbitals), and fourteen for f-sublevel (seven orbitals). This explains that the maximum number of electrons in an orbital is two.
Answer:
Option a, 
Explanation:
According to Arrhenius concept of acids and bases, acids are those substances which releases H+ in aqueous solution and bases are those which releases OH- in aqueous solution.
Among the given only can release 
in aqueous solution.
LiOH releases 
, therefore it is an Arrhenius base.
and 
cannot releases .
So, the correct option is option a.
