TMS stands for Tetramethylsilane
Formula : Si(CH₃)₄
It is used as internal standard for chemical shift
In TMS all the four methyl groups are similar thus all the 12 hydrogen are chemically equivalent. They will show proton NMR at same level and which will appear as a singlet.
We have defined this singlet to be as reference set as zero.
Generally the other organic compounds show chemical shift downfield.So have positive chemical shift with respect to TMS shift.
Wood sinks in ethanol => wood has higher density than ethanol.
wood floats in gasoline=> wood has lower density than gasoline
Answer: it's c. Axial precession
Explanation:
The act of using senses or tools to gather information is making an observation
