Why is gold so easily malleable while iron is so rigid?

Metal, it can be a music genre like hard rock metal, or heavy metal. This type of music developed widely in the United States and the United Kingdon in the late 1960s and early 1970s. It came out of genres blues rock, psychedelic rock, and acid rock. The genre is characterized by a thick, massive sound, highly amplified distortion, extended guitar solos, and emphatic beats and overall loudness. Its lyrics and performance styles are sometimes associated with aggression and machismo. (click here for more details)

But we won’t be digging into this genre of music. Let’s talk about the other world of metal.

Metal in chemistry is any class of substances characterized by high electrical and thermal conductivity, malleability, ductility, and high reflectivity of light. Sometimes it is described as a lattice of positive ions surrounded by a cloud of delocalized electrons. Elements are distinguished by their ionization and bonding properties, and metals are among the three groups, along with metalloids and nonmetals.

Among 118 known elements, approximately three-quarters of them are metals. The elements like aluminum, iron, calcium, sodium, potassium, and magnesium are the most abundant varieties in the Earth’s crust. Ores contain considerable amounts of metals (mineral-bearing substances). Still, some metals like copper, gold, platinum, and silver frequently occur in the free state, not quickly reacting with other elements. (click here for more details)

Gold and iron are both metals. Why is gold so easily malleable while the iron is so rigid?

The atoms of metals can roll over each other into new positions without breaking the metallic bond, making it malleable and ductile. Malleability is a property of a metal that can be hammered, pressed, or rolled into thin sheets without breaking. To put it simply, the metal can be deformed under compression and take on a new shape. Pressure can determine a metal’s malleability. When a metal does not break after a high pressure is acted upon; therefore, it has greater malleability. And the variations in malleability among different metals are due to the differences in their crystal structures. (click here for more details)

Among all metals, gold seems to have the most excellent malleability. By a combination of cold rolling and hammering without any intermediate annealing, it can be reduced to a foil with a thickness of some 50 to 100 nm, about 250 to 500 atoms. (click here for more details)

Both gold and iron are metals, but their atomic structure is different. And the atoms of all metallic elements have distinct atomic structures viz. protons, neutrons, and electrons in varying numbers. These atoms are held in metal through a metallic bond. The sharing of many detached electrons between many positive ions, where the electrons act as a “glue,” gives the substance a definite structure. Metallic bond in iron is much stronger than in gold.

Metals with a high boiling point and a melting point have stronger bonds between their atoms. Iron, an element of group VIII of the periodic table, is a lustrous, ductile, malleable, and silver-grey metal. It is considered the tenth most abundant element in the universe, found in a significant amount at the core of the Earth in a molten form.

Iron has a melting point of 1538°C, while gold can be melted at 1064°C. The boiling point of iron is 2861°C, while gold’s boiling point is at 3080°C. Therefore, gold has stronger atomic bonds than iron, which also makes it more malleable. (click here for more details)

The malleability of metals has made our lives a lot easier and comfortable. Not only do we get glamour with gold, but some gleaming metals like copper and silver are often used for our jewelry, decorations at home or in the office, arts, and coins. Rigid metals such as iron and metal alloys such as stainless steel are used to build homes, hospitals, schools, hotels, ships, and vehicles, including cars, trains, and trucks.

Some specific qualities of metals dictate their usage. For example, copper is used for wiring because it is mainly a good conductor of electricity. Tungsten on the other side is used for the filaments of light bulbs because it glows white-hot without melting. (click here for more details)

For cooking and better food storage, you use aluminum foil to wrap some of the food that you cook. Microcircuits inside your phones are also made of aluminum. Some use it to develop smart coatings for glass that make windows reflective and protective by blocking infrared radiation.