Hmm... I'm unsure but its either B or D.
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:
Km is the biggest measure in width (even if there are bigger measures like Mm, Gm, Tm).
1 Km = 1000 m, 100000 cm and 1000000 mm
Answer:

Explanation:
Hello,
In this case, for a first-order reaction, we can firstly compute the rate constant from the given half-life:

In such a way, the integrated first-order law, allows us to compute the final mass of the substance once 10.0 minutes (600 seconds) have passed:

Best regards.