**False**

Sodium is not a hard metal and can be easily cut with a knife. Let's discuss why this statement is false in detail.

**1. Physical properties of sodium:**
Sodium is a highly reactive alkali metal that belongs to Group 1 of the periodic table. It is a soft, silvery-white metal that can be easily cut with a knife. Sodium has a low melting point of 97.8 degrees Celsius (208 degrees Fahrenheit) and a low boiling point of 882.9 degrees Celsius (1621.2 degrees Fahrenheit).

**2. Reactivity of sodium:**
Sodium is extremely reactive due to its low ionization energy and tendency to lose its outermost electron. It reacts vigorously with water, producing hydrogen gas and sodium hydroxide. This reaction is so exothermic that it can cause the hydrogen gas to ignite, resulting in a fire. Sodium also reacts with oxygen in the air, forming sodium oxide.

**3. Softness of sodium:**
The softness of a metal is determined by its metallic bonding. In metals, the atoms are arranged in a regular pattern called a lattice, and the positive metal ions are surrounded by a sea of delocalized electrons. This arrangement allows the metal to be malleable and ductile, meaning it can be easily hammered or drawn into thin wires.

Sodium has a simple cubic lattice structure, with one sodium atom at each corner of the cube. The delocalized electrons in sodium are not strongly attracted to the positive metal ions, resulting in weak metallic bonding. As a result, sodium is a soft metal that can be easily cut with a knife.

**4. Cutting sodium with a knife:**
When a knife is used to cut sodium, the pressure applied by the knife causes the metal lattice to deform and the delocalized electrons to move aside. This allows the knife to easily slice through the metal, separating it into smaller pieces.

In conclusion, sodium is not a hard metal and can be easily cut with a knife. Its softness is due to the weak metallic bonding resulting from the simple cubic lattice structure and the relatively low attraction between the positive metal ions and delocalized electrons.

This is a false statement.