Question

What do these signs stand for on the periodic table $Ta$, $Os$, $Rh$ $?$
A.Metalloids
B.Metals
C.Nonmetals
D.Gas

Answer 1

First we have to know that $Ta$, $Os$, and $Rh$ are the signs used to denote elements in the modern periodic table. $Ta$ stands for Tantalum, $Os$ stands for Osmium, and $Rh$ stands for Rhodium.
The elements in the periodic table are mainly classified into three types, namely metals, nonmetals and metalloids based on their characteristics.

Complete answer:
In the periodic table, the elements on the left side of the line are metals (except hydrogen), the elements on the right side of the line are nonmetals and the elements just adjacent to a line are metalloids.
Since $Ta$, $Os$, and $Rh$ are the elements located at the centre of the modern periodic table. Then they are all metals. Hence, the signs Ta, $Os$, and $Rh$ stand for metals on the periodic table.
Atomic number of $Ta$ is $73$ and it is a lustrous transition metal. It is used in making electronic equipment. Atomic number of $Rh$ is $45$ and $Rh$ is a silvery white, hard and corrosive resistant metal. Similarly, the atomic number of $Os$ is $76$ and $Os$ is a hard white transition metal.
Hence option B is correct.

Note:
$Ta$, $Os$, and $Rh$ are all transition metals with the same platinum group.
Metals are the substances they form cations because they lose electrons to attain stability. They are good conductors of heat and electricity. Non-metals are the substances they form anions from which gain electrons to gain stability. Whereas, metalloids are the substances which show properties of both metals and nonmetals.