Answer:
3
three half-filled orbitals each capable of forming a single covalent Bond and an additional lone - pair of electrons
One term could be allostasis, the opposite of homeostasis.
Other antonyms of homeostasis, the body's ability to maintain a stable internal environment, include imbalance, instability, etc.
Some potential energy was converted into thermal energy due to friction. The acceleration due to gravity became smaller as the box slid down the ramp.