Answer:
This question lacks options, the options are;
A. Absorption of heat
B. A chemical change
C. A physical change
D. Formation of a new compound
The answer is C. A physical change
Explanation:
A physical change is a type of change that does not involve the chemical composition of the substance(s) involved. Physical changes affect the form but not the chemical content of a substance. Examples of physical changes are freezing, change of state, boiling etc.
In this question, a liquid is cooled during an investigation causing it to solidify. The cooling of this liquid represents a PHYSICAL CHANGE because the liquid state of the substance is only changed to a solid state but does not involve changing the chemical composition of the substance.
True.
A catalyst is a substancr that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
Ca №20
N(e)=20
_______________________
Explanation:
reaction A is exothermic reaction as a substance is produced from two substances
and
reaction B is endothermic as two substances are formed from one complex structure
