Question

Which of the following is a metal?
A. Sodium
B. Chlorine
C. Carbon
D. Fluorine

Answer 1

Hint: We have to remember that a metal is a chemical element, a solid material, which is malleable (metals are hammered into the sheets), shiny, hard, fusible, and ductile. Metal is a good electric conductor and also a thermal conductor. For example iron (chemical element), stainless steel (an alloy), polymeric sulfur nitride (a molecular compound).

Complete step by step answer:
We can also know that the word metal obtained from Greek, metallon, which means quarry, mine and metal.
We must remember that the metals react with air (oxygen) to form oxides. The oxide is formed by electron loss in the metal. This happens in various timescales. Metals are generally basic. But some other elements in the periodic table are not metal, they are called variably by Metalloids, Non-metals, halogens, noble gases.
Let us see the options one by one to find which not the metal is.
Option A. Sodium
We have to know that the sodium, chemical symbol is $(Na)$. It is placed in the group $1$ in the periodic table. It is an alkali metal. It readily loses a single electron in its outer shell, creating a positively charged ion $(N{a^ + })$. Sodium is a metal, but let us see the other options to find the correct one.
Option B. Chlorine
We need to know that the chlorine, chemical symbol is $(Cl)$. It is a halogen (salt-producing) and not a metal. Chlorine does not lose electrons, but it gains electrons and creates negative ions. It is an extremely reactive element.
Now we discuss about the option C. Carbon
As we know that the carbon $(C)$ is the most abundant element in the earth’s crust. And carbon's unusual ability to form polymers at the temperatures commonly encountered on earth. It is the second most abundant element
In the human body. Due to its tetravalency, carbon does not lose or gain electrons. Carbon is a non-metal.
Let we can see the option D. Fluorine
As we know that the Fluorine, chemical symbol is $(F)$. It is the most electronegative element and it is the lightest halogen (salt-producing). Fluorine does not lose electrons, but it gains electrons and creates negative ions. It is an extremely reactive element (but not react with helium and neon).
Therefore, option A is correct.

Note:
We must need to know that sodium is the reactive metal and it is always stored in kerosene because it reacts with oxygen, carbon dioxide and other moisture present in the air and creates fire. In the kerosene, all compounds are already reduced so no further reduction takes place. And also not stored in water.