Left Panel
A is an acid. Not the answer.
B is correct. That would be a base. But it is not an Arrhenius base. Keep reading.
C that is exactly what an Arrhenius base is.
D. No an acid of some sort would accept OH ions.
Right Panel
D is concentrated and it is also a weak base. Good cleaning fluid. Smells awful but it works.
Answer:
How can I tell if a chemical reaction is occurring? A chemical reaction is usually accompanied by easily observed physical effects, such as the emission of heat and light, the formation of a precipitate, the evolution of gas, or a color change.
Explanation:
The atomic number of an element is based on the number of protons in the atomic nuclei of its atoms.
The correct answer is Phospholipid
If a piece of charcoal is taken and set on fire it will evolve CO2 and heat. Charcoal is solid but carbon dioxide is gaseous. This is an example of change of state and evolve of heat during chemical reaction.