Characteristic properties are used because the sample size and the shape of the substance does not matter.
The option that would best contrast the real and the model atoms is letter "D. model of an atom is not as small as an actual atom". The size of an atom is said to be no more than 0.1 to 0.5 nanometers. The models are used to proper illustrate the atom's physical attributes. That is why, it needs to be bigger in size.
Answer: D i think
Explanation: Im sorry if it is wrong lol!! I pretty sure thats the answer...
Answer: A persistent or non-volatile chemical agent can remain on a surface for more than 24 hours.
Explanation:
Non-volatile substance is defined as the one which does not readily evaporate into its surrounding. Generally, a non-volatile substance has strong intermolecular forces between its molecules.
A non-volatile substance will take more than 24 hours to remain on the surface.
On the other hand, a substance with weak intermolecular forces present in its molecules will readily evaporate into the atmosphere.
For example, acetic acid is a volatile substance and quickly evaporates into the atmosphere.
Thus, we can conclude that a persistent or non-volatile chemical agent can remain on a surface for more than 24 hours.