A is automatically wrong since protons have a +1 charge. B is wrong since it states electrons have no charge. C is wrong since it says electrons have no charge. Therefore we are left with D.
The 15th Amendment to the Constitution granted African American men the right to vote by declaring that the "right of citizens of the United States to vote shall not be denied or abridged by the United States or by any state on account of race, color, or previous condition of servitude."
<u>Answer: </u>He sorted on the basis of average atomic weights.
<u>Explanation:</u>
Dmitri Mendeleev in 1863 arranged chemical elements in the groups according to their average atomic weights.
He said that elements which have similar chemical properties either have similar atomic weights or their atomic weights increases regularly.
Hence, he collaborated a great work in sorting the elements according to their average atomic weights.
Answer: 1.77 kg of manganese (IV) oxide reacts to produce 1.12kg of manganese metal.
Explanation:
The balanced chemical equation is:
To calculate the moles, we use the equation:
moles of manganese = 
According to stoichiometry :
3 moles of 
is produced by = 3 moles of 
Thus 20.4 moles of is produced by =
of
Mass of 
(1kg=1000g)
Thus 1.77 kg of manganese (IV) oxide reacts to produce 1.12kg of manganese metal.
Answer:
Both Option (I) and Option (III)
Explanation:
Biomass is usually defined as those organic molecules that are obtained from plants and animals, in order to produce energy. It is a renewable resource. Some of the examples of biomass include wood, crop, animal fossil fuel.
A large number of trees are being cut down to construct these biomass energies such as woods. This results in the deforestation process where the forested areas are converted into empty dry soils. This results in the increasing rate of erosion because the prevailing wind and flowing water can easily carry away the topsoil and loses the fertility of the soil.
Thus, the correct answers are both options (I) and (III).
