The refractive index, n of a polymer was determined as a function of temperature. The results are given in the table. Determine the glass transition temperature of the polymer. T/°C 20 30 40 50 60 70 80 90 100 110 120 130 n 1.5913 1.5898 1.5883 1.5868 1.5853 1.5838 1.5822 1.5801 1.5766 1.5725 1.5684 1.5643

Explanation:

The given data shows linear trend between refractive index and temperature .

From 20 degree to 80 degree , every increase of 10 degree decreases refractive index by .0015 . This trend breaks at 90 degree beyond which , refractive index falls at greater rate or sharply.

So transition temperature is 90 degree .

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.