<span><span>Number of Protons-19 </span><span>Number of Neutrons-20 </span><span>Number of Electrons-<span>19</span></span></span>
Answer: (3) ppm
Explanation: Concentration is defined as the amount of solute dissolved in a known amount of the solvent or a solution.
Parts per million (ppm) is used to express the concentration when a very small quantity of solute is present in a large quantity of the solution. It is defined as the mass of solute present in one milion
parts by mass of the solution.

L/s is used to express flow rate.
J/g is used to express energy per unit mass.
kPa is used to express pressure.
Answer:
A link is a fastening unit that attaches two parts of an object together
Different types of links have different characteristics
Answer:
When octane and oxygen gas are burned in our cars, carbon dioxide and water come out of the exhaust. The increase in carbon dioxide in the atmosphere is causing global warming. 4.
Explanation: