Video Transcript
Which of the following is not a common property of metals? (A) High mechanical strength, (B) bright color, (C) high thermal conductivity, (D) high electrical conductivity, or (E) high melting point.
A property is an attribute or quality or characteristic by which we can describe something. In general, all metals, whether they be elements or alloy mixtures, have similar properties. This is because metals all have the same structure or at least very similar structures. Metals are made of giant lattices of positively charged ions surrounded by delocalized valence electrons.
Metallic bonds hold the particles together. Metallic bonds are strong electrostatic forces between these oppositely charged particles. And it is these metallic bonds which influence some of the properties of metals. A lot of thermal or mechanical energy is required to overcome these bonds in melting a solid metal or breaking a piece of metal.
The question asked which of the following is not a common property of metals. We have seen that high mechanical strength and high melting point are properties of metals. And so these cannot be the answers. We can rule out answer options (A) and (E). The delocalized valence electrons in the metallic lattice are free to move. This enables metals to conduct heat energy very well as well as conduct electrical current. We can rule out answer options (C) and (D) as these answer options are common properties of metals.
We are left with answer option (B) bright color. In our daily lives, we have all seen some of the more commonly known metals, and we know that most are a silver-gray color. Except for metals like copper, which is orange in color, and gold, which has a shiny yellow color, most metals do not display bright color. Finally, which of the following is not a common property of metals? The answer is (B) bright color.
