Question

Arrange the following metals in the decreasing order of chemical reactivity placing the most active first. The metals are ${\text{Cu, Mg, Fe, Na, Ca, Zn}}$.
A) ${\text{Na}} > {\text{Ca}} > {\text{Mg}} > {\text{Zn}} > {\text{Fe}} > {\text{Cu}}({\text{leastactive}})$
B) ${\text{Na}} > {\text{Ca}} > {\text{Mg}} > {\text{Zn}} > {\text{Cu}} > {\text{Fe}}({\text{leastactive}})$
C) ${\text{Na}} > {\text{Mg}} > {\text{Ca}} > {\text{Zn}} > {\text{Fe}} > {\text{Cu}}({\text{leastactive}})$
D) ${\text{Na}} > {\text{Mg}} > {\text{Zn}} > {\text{Ca}} > {\text{Fe}} > {\text{Cu}}({\text{leastactive}})$

Answer 1

Hint: The reactivity of a metal depends upon the tendency of a metal to accept or donate an electron to the other reactant. The size and the valence electrons matter the most while determining the reactivity of a metal. One can analyze the given metals according to these concepts and decide the correct order of reactivity as shown in options.

Complete step by step answer:
1) First of all we will analyze the given metals in question one by one and discuss its reactivity depending on the factors. The copper ${\text{(Cu)}}$ metal is situated period four and has two valence electrons.
2) The metal magnesium is situated in period three and has two valence electrons. The metal iron ${\text{(Fe)}}$ is situated in period four and has two or three valence electrons. The sodium metal is situated in period three and has only one valence electron. The calcium metal is situated in period four and has two valence electrons present. The metal zinc is located in period four and has two valence electrons.
3) There is the order of reactivity of metals and in order to remember this order, one has to recite this order in any possible simple form. The order of reactivity of metals is as follows,
Potassium > Sodium > Lithium > Calcium > Magnesium > Aluminium > Zinc > Iron > Copper > Silver > Gold.
4) Therefore, according to this order, we can arrange the order of reactivity of metals given in the question as, ${\text{Na}} > {\text{Ca}} > {\text{Mg}} > {\text{Zn}} > {\text{Fe}} > {\text{Cu}}({\text{leastactive}})$
Hence, option A is the correct answer.

Note:
To remember the order of reactivity of metals there is a little trick sentence as, Please Stop Calling Me A Cute Zebra I Like Her Call Smart Goat where each word's first letter relates to the name of metal.