Chemistry

The function of pressure regulators in the emission system of flame photometer is to have a steady flame which is free from flickers?

• True

• False

Which of the following is the principle of Flame emission photometers?

• Radiation is absorbed by non-excited atoms in vapour state and are excited to higher states

• Medium absorbs radiation and transmitted radiation is measured

• Colour and wavelength of the flame is measured

• Only wavelength of the flame is measured

The detector converts IR radiation into __________ signals and sends it to the recorder.

The spectral region is split into ___________

Internal conversion comes under …………………………

• Non radiative transition

• Radiative Transition

• Both

• Not a type of Transition

In Intersystem crossing (ISC), the energy of the activated molecule is dissipated through …………………

• Molecular collisions

• Transitions between states of different spins

• Physical contact of an excited molecule with other particles

• None of the Above

Fluorescence happens when molecule from singlet state returns to ……………………………

• Higher state

• Lower state

• Ground state

• None of the above

In fluorescence, absorption of energy by atoms or molecules followed by .............. emission of light.

• Moderate

• Delayed

• Immediate

• None of the above

Phosphorescent emission of light can persist after the radiation used to excite the molecules has been turned off. True or False?

• True

• False

Why are Phosphorescence measurements usually made at a low temperature?

• Triplet excited state to singlet ground state

• Singlet ground state to singlet excited stated

• Triplet ground stated to singlet excited stated

• None of the Above