Here's why:

* Newton's Second Law: This fundamental law of physics states that force is directly proportional to mass (in kilograms) and acceleration (in meters per second squared).

* Derivation: Therefore, 1 Newton is defined as the force required to accelerate a 1 kilogram mass at a rate of 1 meter per second squared: 1 N = 1 kg * 1 m/s².

While the Newton is the standard unit, you might encounter other units in specific contexts:

* Pound-force (lbf): Often used in engineering and everyday applications.

* Dyne (dyn): A smaller unit, sometimes used in scientific contexts.

* Kilogram-force (kgf): A unit equal to the force exerted by gravity on a 1 kilogram mass.

However, it's generally best to stick to the standard unit of the Newton for consistency and clarity.