Which of the following statements are true regarding the effect of flame temperature on atomic absorbance and atomic emission spectroscopy?

i. varying the flame temperature by 10 k hardly affects the ground-state population of the analyte and would not noticeably affect the analyte signal in atomic absorption.
ii. varying the flame temperature by 10 k hardly affects the excited-state population of the analyte and would not noticeably affect the analyte signal in atomic emission.
iii. varying the flame temperature by 10 k affects the ground-state population of the analyte and will noticeably affect the analyte signal in atomic absorption.
iv. varying the flame temperature by 10 k affects the excited-state population of the analyte and will noticeably affect the analyte signal in atomic emission.
select one:

a. i and ii
b. iii and iv
c. i and iv
d. ii and iv
e. ii and iii

the correct option is option c, I and IV

Explanation:

Atomic emission spectroscopy is used to determine quantity of element in a sample.

Atomic emission spectroscopy based on occurring of atomic emission when a valence electron from higher energy orbital comes back to lower energy orbital.

Light intensity emitted by a flame, plasma, arc of particular wavelength are used to excite the valence electron.

The intensity of atomic emission lines are proportional to number of atoms present in the excited state.

Emission intensity is affected by temperature of the excitation source and the efficiency of atomization.

Increase in temperature does not affect the ground state population.

Therefore, statements I and IV are correct.

So, the correct option is c.

the correct answer is a

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.