The phrase "are less reactive than" is correct and usable in written English.
It can be used when comparing the reactivity of two or more substances or elements in a scientific context.
Example: "In general, noble gases are less reactive than alkali metals due to their full valence electron shells."
Alternatives: "are not as reactive as" or "exhibit lower reactivity compared to".
When the halogen acts as a functional group, aryl halides are less reactive than alkyl halides and more closely resemble vinylic halides in their reactivity.
The results obtained in this study confirm that cycloalkanes are less reactive than their non-cyclic counterparts.
Model soot samples are less reactive than real soot samples, which can be attributed, mainly, to a lower proportion in heteroatoms and a higher graphitic order for the case of one of the carbon blacks.
Since the hydroxyl end-groups of PCL are less reactive than the triethoxysilane counterparts, the preliminary reaction of the hydroxyl end-groups with 3-isocyanatopropyltriethoxysilane is recommended for decreasing the gelation time and the amount of PCL extractable from the final hybrid material.
Additionally, as they are less reactive than calcites, dolomites are less likely to lose porosity with depth due to dissolution or re-precipitation (Grammer and Harrison 2003).
However, it was previously described that these type of monomers are less reactive than unmodified methacrylate, which yields slower polymerization rates [23].
Although 1,4-divinylbenzene is a styrene derivative, it was higher in monomer reactivity than styrene, but its chain-end anion was less reactive than that generated from styrene.
Results from real-time FTIR spectroscopic studies indicated that ethoxy was less reactive than methoxy substituent.
Crystalline silicon is less reactive than finely divided and, possibly, amorphous silicon.
Initially, clean Pt(111) is less reactive than clean Pt(110) even in the electrochemical environment.
The models also indicate that PP is less reactive than LLDPE.
