Which of the follow is not a physical change? a. The boiling of room temperature water to produce steam.
b. The combustion of hydrogen gas and oxygen gas to produce liquid water.
c. The cutting of a block of sharp cheddar cheese to make smaller pieces for hors d'oeuvres for a social gathering
d. The slow melting of solid coconut oil on the stove.

d. The slow melting of solid coconut oil on the stove.

Explanation:

Matter can exist in three major states; solid, liquid and gas. These state can be converted from one to another through various processes that could lead to a physical or chemical change or both.

A physical change is a process that involves the transformation, i.e change of state, of a substance with no chemical change. While a chemical change would produce one or more products different from the initial substance.

From the question, the slow melting of solid coconut oil on the stove requires both physical and chemical change.

a boiling water reactor does not boil the water. a pressurized water reactor boils the water faster. a pressurized water reactor is heated directly by the core. a pressurized water reactor does not use fission.

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.