Answer:
It takes 1.9 
years to distribute all the grains.
Explanation:
In one second, 
grains of wheat are distributed.
We are supposed to find the time it would take to Distribute Avogadro number of grains.
1 avogadro number = 6.022 
Number of grains distributed in 1 day = 86400 
= 8.64 
Number of grains distributed in 1 year= 8.64 
= 3.1536 
Time taken = 
= 
= 1.9
Answer : The disadvantage of using hydropower is Land can be flooded, displacing people and wildlife
Explanation :
Hydropower is a renewable source of energy. In hydropower, electricity is generated using the mechanical energy of moving water.
Since the kinetic energy is necessary to move the turbines, it is essential that the hydropower plant is present near a water source which has moving water.
It is the most efficient way of harnessing the energy from naturally available energy sources. It does not produce any waste. It does not pollute water or air.
Since hydropower needs kinetic energy of moving water, there is always a possibility of nearby land getting flooded. This would affect the people and wildlife of nearby areas.
Therefore the disadvantage of using hydropower is that land can be flooded, displacing people and wildlife
The correct option is B. To get the number of atom for each compound, each element in the compound will be counted as an atom. For instance, for Fe[ClO4]2, there are 1 atom of Fe, 2 atoms of Cl, and 8 atoms of O, making a total of 11 atoms [1 + 2 + 8= 11]. The other options have less than 11 atoms.
Bismuth-209 (209Bi) is the isotope of bismuth with the longest known half-life of any radioisotope that undergoes α-decay (alpha decay). It has 83 protons and a magic number of 126 neutrons, and an atomic mass of 208.9803987 amu (atomic mass units). Of the first 82 elements in the periodic table, 80 have isotopes considered to be stable.[1] The 83rd element, bismuth, was traditionally regarded as having the heaviest stable isotope, bismuth-209, but in 2003 researchers in Orsay, France, measured the half-life of 209
Bi
to be 1.9×1019 years.[2][3] Technetium and promethium (atomic numbers 43 and 61, respectively[a]) and all the elements with an atomic number over 82 only have isotopes that are known to decompose through radioactive decay. No undiscovered elements are expected to be stable; therefore, lead is considered the heaviest stable element. However, it is possible that some isotopes that are now considered stable will be revealed to decay with extremely long half-lives (as with 209
Bi
). This list depicts what is agreed upon by the consensus of the scientific community as of 2019.
