In order of decreasing reactivity, the metals potassium, sodium, lithium, calcium, magnesium, zinc, iron and copper can be put in order of their reactivity from their reactions with water and dilute acids.
Aluminium is more reactive than Magnesium.
Potassium metal is indeed more reactive than lithium metal, because potassium has a more loosely bound valence electron. In direct reactions, potassium reacts more violently than lithium.
Flexi Says: The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive.
Concept: The alkali metals are soft and silvery. They are also the most reactive metals having the lowest ionization energies. They react readily with water, lithium being the least reactive and potassium the most.
The alkaline earth metals are the second most reactive family of elements. Beryllium, magnesium, calcium, strontium, barium and radium are all shiny, and silvery-white.
Lithium is the least reactive because it is the one with the least electrons. That means the electrons are closer to the nucleus and therefore more attracted to it.
Reactivity. Lithium is part of the Group 1 Alkali Metals, which are highly reactive and are never found in their pure form in nature. This is due to their electron configuration, in that they have a single valence electron (Figure 1) which is very easily given up in order to create bonds and form compounds.
Hence, option (A) is correct., Lithium is the lightest metal.
Magnesium is another element that is highly reactive, so it is not found in a pure state on Earth, unless a crazy-haired chemist has produced a pure chunk of vapor-deposited magnesium crystals using the Pidgeon process, as you see in the image at the top.
These findings are consistent with a hypothesis that lithium inhibits magnesium-dependent enzymes by displacing magnesium from its binding site thereby reducing the structural stability and lowering activity of the enzyme.
The arrangement of metals as per reactivity series is: K > Na > Ca > Mg > Al > Zn > Fe > Ni > Sn > Pb > H > Cu > Ag > Au.
- So, out of given metals, Potassium is the most reactive metal.
We can therefore confirm their order of reactivity (from most reactive to least) as: potassium, magnesium then zinc.
Magnesium does not react with cold water because it is coated with insoluble Magnesium hydroxide, which prevents water from coming into contact with it.
As the size of the ion is small it has more force of attraction and hence it requires a lot of energy to break the bond and therefore it is more stable.
It has the lowest density of all metals. It reacts vigorously with water. The most important use of lithium is in rechargeable batteries for mobile phones, laptops, digital cameras and electric vehicles. Lithium is also used in some non-rechargeable batteries for things like heart pacemakers, toys and clocks.
This is in part due to a decrease in ionization energy down the group, and in part to a decrease in atomization energy reflecting weaker metallic bonds from lithium to cesium. This leads to lower activation energies, and therefore faster reactions.
Lithium metal reacts vigorously with all the halogens to form lithium halides. So, it reacts with fluorine, F2, chlorine, Cl2, bromine, I2, and iodine, I2, to form respectively lithium(I) fluoride, LiF, lithium(I) chloride, LiCl, lithium(I) bromide, LiBr, and lithium(I) iodide, LiI.
Alkali metals (lithium, sodium, potassium) are so soft that they can be cut with a knife.
Lithium is the softest metal in the periodic table.
Caesium, the most reactive metal in the periodic table, reacts extremely violently – hence why it can't be demonstrated in a classroom! This can be compared to other common metals, such as iron and copper, which produce no reaction when dropped into water.
From the reactivity series, the order of reactivity is Magnesium (Mg) > Aluminium (Al) > Zinc (Zn) > Iron (Fe). So, magnesium is the most reactive among the given metals and thus it's rate of reaction will be fastest (to react with steam).
Metallic character is associated with the elements that are metals. Most of the metals are hard, have high melting/boiling points, and are malleable as well as ductile. Among Sodium and Potassium, Potassium is the most reactive metal as it has lower ionization energy than sodium due to its bigger atomic size.