Video Transcript
Which of the following elements is not a metalloid? (A) Boron, (B) magnesium, (C) germanium, (D) arsenic, or (E) antimony.
The elements are located on the periodic table according to specific properties. Those elements shown in orange are metals. As we can see, the periodic table is primarily composed of metal elements, including the lanthanides and actinides at the bottom.
Metals tend to have similar properties to each other. A cleaned metal surface tends to be lustrous or shiny. Metals are ductile. That is, they can be pulled or drawn into long, thin wires. Metals are also malleable. That is, they can be hammered into thin, flat sheets. Metals tend to be excellent thermal conductors, as well as electrical conductors.
Nonmetals, shown in pink, are also grouped together on the periodic table, except for hydrogen all the way on the left in group one. Nonmetal solids tend to be dull, while gases tend to be colorless. Nonmetals are inductile and cannot be pulled into long, thin wires. They are also not malleable. When hammered, nonmetal solids tend to crack or shatter. We say they are brittle. Nonmetals also tend to be poor conductors of heat and electricity, although there are some exceptions, like carbon in graphite.
The main difference between metals and nonmetals are the forces between the atoms. These forces cause there to be a difference in both physical and chemical properties. Another grouping on the periodic table are the metalloids, sometimes known as semimetals. Metalloids have the physical and chemical properties of both metals and nonmetals. The elements shown in black are poorly understood. And so we have not classified them as metal, metalloid, or nonmetal.
The question asked us to identify the element which is not a metalloid. Let’s see where each of our five answer options are located on the periodic table.
Boron is located in group 13 and is a metalloid. So we can rule out answer option (A) boron.
Magnesium is located in group two. It is not a metalloid; it is a metal. And so answer option (B) is our answer. Let’s confirm this by looking at the other answer options.
Germanium is in group 14, and it is a metalloid. So we can rule out answer option (C).
Arsenic is also a metalloid, and it is in group 16. We can rule out answer option (D) arsenic.
Antimony, symbol Sb, is also in group 16, and it is a metalloid. So we can rule out answer option (E).
Finally, which element is not a metalloid? The answer is (B) magnesium.
