Answer:
10 x 5 = 50
Explanation:
50 is the mass of her chemical.
Answer : The correct option is, (2) Cr (Chromium)
Explanation :
The reactivity series of metal are arranged of the reactivity from the highest to the lowest. Reactivity series is used to determine the products of the single displacement reactions. In the single displacement reaction, the most reactive metal displaces the least reactive metal.
From the given reactivity series we conclude that there are two metal (Mg and Cr) are more reactive metal than the Ni and there are two metal (Pb and Cr) are less reactive metal than the Zn. So, the Cr (Chromium) is the metal which is more active than Ni and less active than Zn.
Hence, the correct option is, (2) Cr
The answer is AIM NOT POSTIVE

This reaction is called decomposition reaction, furthermore it can be said to be decomposition of limestone.
The balanced chemical equation for the reaction is ~

False! Primary succession is when a community has to completely start over which takes a long time.