Answer:
14.7 lbs
Explanation:
Air pressure is the weight of the air above us. It is approximately 14.7 pounds or lbs per square inch at sea level. It means that an air column weights 14.7 lbs, 1 square inch in diameter, reaching all the way up to the top of the atmosphere.
Answer:
Fossils, the shape of continents, the mid-ocean ridge system, sea floor sediment deposits, and the magnetism of rocks.
Explanation:
Fossils, the continent's shape, the mid-ocean ridge system, sea floor sediment deposits, and the magnetism of rocks on the sea floor are the evidences that support the theory of plate tectonics in the area. Fossils provides information to us when and where plants and animals once existed. Due to diverging plates, some life became isolated, and evolved into new species. Continental ‘fit’ through coastline matching. Some division of continents look as though they should fit together, e.g. South America and Africa.
When finding the moles in a compound you have to know the grams. In this case, 25.2 grams are given for KMnO4. To find the moles you would divide the amount of grams by the molar mass of KMnO4. The molar mass of KmnO4 is 158.034. You you would now divide 25.2 by 158.034 which is 0.15946 moles. Depending on how many decimal places the questions asks for is dependent on you. I just went with 5 significant figures.
Answer: Option (b) is the correct answer.
Explanation:
The elements which have excess or deficiency of electrons will react readily.
Atomic number of Mn is 25 and electronic configuration of 
is [Ar]
. This configuration is stable.
Atomic number of Cr is 24 and electronic configuration of 
is [Ar]
. This configuration is not stable.
Atomic number of Fe is 26 and electronic configuration of 
is [Ar]
. This configuration is stable.
Atomic number of Cu is 29 and electronic configuration of 
is [Ar]
. This configuration is not stable.
Atomic number of Al is 13 and electronic configuration of Al is 
. This configuration is not stable.
Atomic number of Ba is 56 and electronic configuration of 
is [Kr]
. This configuration is stable.
Atomic number of Mg is 12 and electronic configuration of 
is 
. This configuration is stable.
Atomic number of Sn is 50 and electronic configuration of Sn is [Kr]
. This configuration is stable.
Thus, we can conclude that out of the given options, only Fe and reactants would lead to a spontaneous reaction as they have incomplete sub-shells. Therefore, in order to gain stability they will readily react.
