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:
B. This is because the Hydrogen and Oxygen need balanced out.
Current-
C-1 | C-1
H-4 | H-2
O-2 | O-3
Adding a coefficient of 2 before oxygen in the reactants and H2O in the products would balance this equation
<span>CH4 + 2O2 → CO2 + 2H2O</span>
C-1 | C-1
H-4 | H-4
O-4 | O-4
<span>C. Carbon. H. Hydrogen. N. Nitrogen. O. Oxygen. P. Phosphorus. <span>S. Sulfur.</span></span>