Here's why:

* Gravity: The force of gravity acts on all objects with mass.

* Acceleration due to Gravity: On Earth, the acceleration due to gravity is approximately 9.8 m/s².

* Newton's Second Law: This law states that force (F) equals mass (m) times acceleration (a): F = m * a.

Calculation:

* Mass (m) = 1.0 kg

* Acceleration due to gravity (a) = 9.8 m/s²

* Force (F) = 1.0 kg * 9.8 m/s² = 9.8 N