Aseed crystal of diameter d (mm) is placed in a solution of dissolved salt, and new crystal are observed to nucleate (form) at a constant rate r (crystals/min). experiments with seed crystals of different sizes show that the rate of nucleation varies with the seed crystal diameter as: r(crystals/min)= 100-20d a) what are the units of the constants 100 and 20? (assume the given equation is valid and therefore dimensionally homogenous). b) calculate the crystal nucleation rate in crystal/s corresponding to a crystal diameter of 0.050 in. 3 c) derive a formula for r(crystals/s) in terms of d (in).

1.cause they have wings

2.cause they are insects

3.cause they are

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

the answer is 0.42 is that is an option. this question provides no info