Answer:
Various limitations of Mendeleev's periodic table are:-
Position of hydrogen - he couldn't assign a correct position to hydrogen as it showed properties of both alkali and halogens .
Position of isotopes - he considered that the properties of elements are a function of their atomic masses. Hence isotopes of a same element couldn't be placed.
In the d-block , elements with lower atomic number were placed before higher atomic number.
Explanation:
The fewer the carbon atoms, the closer it is to being a gas. The only one you have to check out is A which is hexane. You know that gasoline at the pumps has 8 carbons and its a liquid. So B and C are both not gases because they are above 8.
C6 (hexane) is a liquid at room temperature not a gas.
The answer is D. If there is a gas present, it must be C3
Answer: oil spill, forest fire
Explanation:
The short term environmental change is a change that occur in an environment which exerts it's effect over the environment and the living beings for a short duration. The damage caused by the short term environmental change can be recovered in a short time. The oil spill and forests fire are the example of short term environmental changes.
The oil spill will reduce the abundance of the aquatic species until the oil is circulated out at the bay of the water body therefore, it is a short term environmental change.
Forests fire will remain ignited for a short period but can be destructive enough to cause damage to flora and fauna species. As time passes the reduced populations of flora and fauna can be recovered again.
