Problems

答案

1.Single choice

1）（　　）is the number of oscillations of the field which occur each second.

A.Wavelength

B.Wavenumber

C.Frequency

D.Velocity

2）（　　）is not a spectroscopic technique as it does not make use of electromagnetic radiation.

A.IR

B.UV

C.NMR

D.MS

3）Which of the following technique use the longest electromagnetic radiation（　　）.

A.IR

B.UV

C.NMR

D.X-ray crystallography

4）Which of the following component do not belong to the energy states in a molecule（　　）.

A.electronic

B static

C.vibrational

D.rotational

5）（　　）is absorbed by matter resulting in rotation and/or vibration of molecules.

A.Infrared radiation

B.Ultraviolet

C.Visible wavelengths

D.Radio waves

6）In（　　），the sample is destroyed.

A.mass spectrometry

B.IR

C.UV

D.X-ray crystallography

2.True of false

1）Spectroscopy is a general term referring to the interactions of various types of electromagnetic radiation with matter.　　（　　）

2）At room temperature，most molecules are in the excited state.　　（　　）

3）The amount of energy absorbed in this transition is usually smaller than the energy difference between the states.　　（　　）

4）In all spectroscopic techniques only very small quantities（milligrams or less）of sample are required.　　（　　）

5）An electron that has been excited from the ground state to an excited state can simply return back to the ground state releasing the same wavelength of radiation that was adsorbed in the transition to the excited state.　　（　　）

3.Answer the following questions

1）Please simply describe the functions of five spectroscopic techniques.

2）Please simply describe the composition of electromagnetic spectrum.