Gallium arsenide, gaas, has gained widespread use in semiconductor devices that convert light and electrical signals in fiber-optic communications systems. gallium consists of 60.% 69ga and 40.% 71ga. arsenic has only one naturally occurring isotope, 75as. gallium arsenide is a polymeric material, but its mass spectrum shows fragments with the formulas gaas and ga2as2. what would the distribution of peaks look like for these two fragments?

Five peaks  

Explanation:

GaAs would show two peaks:

Ga-69 + As-75 = 144

Ga-71 + As-75 = 146

Their intensities are in the ratio 60 : 40 = 100:67.

Ga₂S₂ would show three peaks:

Ga-69 + Ga-69 + 2As-75 = (Ga-69)₂(As-75)₂ = 288

Ga-69 + Ga-71 + 2As-75 = (Ga-69)(Ga-71(As-75)₂ = 290

Ga-71 + Ga-71 + 2As-75 = (Ga-71)₂(As-75)₂ = 292

Their relative intensities are in the ratio

(60 + 40)² = 60² : 2×60×40 : 40² = 3600 : 4800 : 1600 = 75 : 100 : 33

A spectrum of a mixture of GaAs and Ga₂As₂ would show five peaks:

Two at m/e 144 and 146 with intensity ratios 100: 67 and

Three at m/e 288, 290, and 292 with intensity ratios 75:100 :33.

We cannot predict the absolute sizes of the peaks because we do not know the relative amounts of GaAs and GaAs₂.

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.