The question asks for the specific term that describes the shining surface property of metals in their pure state. This is a direct definition-based question from the properties of metals.
Correct Option: A) Metallic Lustre
Metallic lustre is the characteristic shining appearance of metals. This property is due to the presence of free electrons in the metallic lattice, which absorb and re-emit light, giving metals their typical shiny look.
The question asks to identify the most ductile metal among the given options. Ductility is a physical property of a material, primarily metals, that describes its ability to be drawn into thin wires without breaking. We need to recall the properties of the given substances.
Correct Option: C) Gold is considered the most ductile metal. It can be drawn into extremely fine wires, a property that is utilized in various applications, including electronics and jewelry.
The question asks about the common physical state of metals at room temperature, noting the exception of mercury. Understanding the general properties of metals is key to answering this.
Correct Option: B) Solids — Most metals, due to their strong metallic bonding and high melting points, exist as solids at room temperature. Mercury is the well-known exception, being a liquid.
The question asks to identify a non-metal that exhibits allotropy, meaning it can exist in different structural forms. We need to evaluate the given options based on their known allotropic properties.
Correct Option: D) Carbon — Carbon is a non-metal that exhibits allotropy, existing in various forms such as diamond, graphite, fullerenes, and graphene, each with distinct physical and chemical properties.
The question asks to identify an allotrope of carbon that is the hardest natural substance and has very high melting and boiling points. We need to recall the properties of carbon allotropes and compare them with the given options.
Correct Option: C) Diamond
The question asks about the conductive property of graphite, an allotrope of carbon. We need to identify what graphite conducts based on its well-known physical and chemical properties.
Correct Option: A) Electricity. Graphite is well-known for its ability to conduct electricity due to the presence of delocalized electrons in its layered structure.