Problem 119

Question

Which of the following is arranged in the order of decreasing electropositive character ? (a) \(\mathrm{Fe}, \mathrm{Mg}, \mathrm{Cu}\) (b) \(\mathrm{Mg}, \mathrm{Cu}, \mathrm{Fe}\) (c) \(\mathrm{Mg}, \mathrm{Fe}, \mathrm{Cu}\) (d) \(\mathrm{Cu}, \mathrm{Fe}, \mathrm{Mg}\)

Step-by-Step Solution

Verified
Answer
Option (c) Mg, Fe, Cu is the correct order of decreasing electropositive character.
1Step 1: Understand Electropositive Character
Electropositive character refers to the tendency of an element to lose electrons and form positive ions. In the periodic table, this character tends to decrease as you move from left to right across a period and increases as you move down a group.
2Step 2: Analyze the Given Elements
Consider the elements given: Magnesium (Mg), Iron (Fe), and Copper (Cu). Mg is an alkaline earth metal, Fe is a transition metal, and Cu is also a transition metal. The electropositive character is generally higher for alkaline earth metals compared to transition metals.
3Step 3: Compare Electropositive Character
Generally, the electropositive character decreases from Mg to Fe to Cu. This is because Mg is more electropositive than Fe and Cu being the least electropositive since transition metals have less tendency to lose electrons compared to alkaline earth metals.
4Step 4: Determine the Correct Order
The correct decreasing order of electropositive character for the given elements is Mg, Fe, Cu. Checking through all the options, (c) is the correct choice.

Key Concepts

Alkaline Earth MetalsTransition MetalsPeriodic Table Trends
Alkaline Earth Metals
The Alkaline Earth Metals are in Group 2 of the periodic table and include elements like Magnesium (Mg) and Calcium (Ca). These metals are known for their high electropositive character, which means they easily lose electrons to form positive ions. This tendency is due to their electronic configuration, which generally ends in
  • "s2".
This configuration makes it relatively easy for them to lose two electrons and gain a stable octet structure.

These metals are highly reactive, particularly with water and oxygen. For example, Magnesium reacts with water to form Magnesium hydroxide and Hydrogen gas. Due to their high reactivity, especially with nonmetals, they are often found in nature only in compound forms, rather than as free metals.
The electropositive character of these elements increases as you move down the group, meaning each element is more willing to lose electrons than the one above it.
Transition Metals
Transition Metals are found in the center of the periodic table, spanning from groups 3 to 12. Unlike Alkaline Earth Metals, Transition Metals like Iron (Fe) and Copper (Cu) have electrons in the "d" subshells, giving them unique properties.

These metals have a range of oxidation states and can form a variety of different ions. This characteristic is why they're less electropositive than Alkaline Earth Metals. Transition metals have a less pronounced tendency to lose electrons, which correlates with their ability to form colorful compounds and powerful magnets.

Another key feature is their ability to form complex compounds. Metals like Copper, for instance, can form complex ions with molecules like water and ammonia. This gives them great versatility and makes them important in industrial applications, from structural materials to catalysts in chemical reactions.
Periodic Table Trends
The periodic table is designed to organize elements in a logical and insightful manner, with electropositivity being one of the key trends you can observe.
  • Across a period: As you move from left to right, electropositive character decreases. This is because elements on the right have more filled valence shells, making them less willing to lose electrons.
  • Down a group: Electropositive character increases because additional electron shells are added, which makes it easier for atoms to lose their outer electrons.
Understanding these trends is crucial for predicting how different elements will behave in chemical reactions.

For example, Magnesium (closer to the left and lower on the periodic table) loses electrons more readily than Iron or Copper. In problem-solving, identifying these trends helps determine properties like reactivity and bonding nature.