Definition of Metals
Metals are a group of chemical elements that possess specific characteristics such as a shining surface, malleability, ductility, and high conductivity towards heat and electricity. These properties make metals highly valuable in various industrial applications.

Shining Surface
- Metals have a characteristic shiny appearance, often referred to as metallic luster. This shining surface is a result of the way that metals reflect light due to their unique atomic structure.
- When light interacts with the free electrons present in metals, it is absorbed and reemitted, giving metals their characteristic shine.

Malleability
- Malleability refers to the ability of a substance to be beaten into thin sheets without breaking or cracking.
- Metals exhibit high malleability due to the presence of metallic bonds, which allow the layers of atoms to slide past each other when a force is applied. This property enables metals to be easily shaped and formed into various objects.

Ductility
- Ductility is the property of a material to be stretched into thin wires without breaking.
- Metals possess high ductility because of the metallic bonding. The free electrons in metals allow the atoms to slide past each other, enabling the metal to be drawn into thin wires.

Conductivity towards Heat and Electricity
- Metals are excellent conductors of heat and electricity. This means they allow the flow of thermal energy and electric current through them with minimal resistance.
- The high conductivity of metals can be attributed to the presence of delocalized electrons, which are not bound to a specific atom. These electrons are able to move freely through the metal lattice, carrying heat or electricity.

Classification of Metals
Based on these specific properties, elements that exhibit a shining surface, malleability, ductility, and high conductivity towards heat and electricity are classified as metals. This classification helps distinguish metals from non-metals and metalloids, which may lack one or more of these properties.

Overall, the properties of metals make them essential in various industries, including construction, electrical engineering, and manufacturing, where their malleability, ductility, and conductivity are highly valued.