Santa maria has an elevation of 6.30 times 10 to the 5th mm. how many km is the elevation?

The measurement of height can be expressed in terms of meter, from kilometer to millimeter or sometimes for very less distance the scale can be reduced to micro or nano meter also. Here the change of the elevation of Maria is from 6.30 times of 10 to the 5th. The elevation have to be transferred in terms of kilometer. The 6.30 times of 10 is 6.30×10⁵ mm= 0.63 kilometer as 1 mm is equivalent to Km. Thus 6.30×10⁵ mm is equivalent to 0.63 Km. Thus the elevation of Santa Maria is 0.63 Km.

D. Cd(NO3)2 + Na2S -> CdS + 2 NaNO3​

Explanation;

A double displacement reaction is a type of chemical reaction that takes place when two compounds reacts, and the positively charged ions or cations and the negatively charged ions or anions of the two reactants switch places resulting to the formation of two new compounds.

In this case; the reaction Cd(NO3)2 + Na2S -> CdS + 2 NaNO3​; is an example of double displacement reaction, in which Cd2+ ions in Cd(NO3)2 switch places with Na+, while NO3- in Cd(NO3)2 switch places with S^2- in Na2S, to form two new compounds CdS and  NaNO3​.

Explanation: