Which is a sign of a chemical change? a) ice cream left at room temperature melts. b) calcium chloride is dissolved in h2o and disappears. c) paint on a freshly painted wall dries and is no longer sticky. d)when h2s gas is bubbled into a lead acetate solution, a precipitate forms.

The agent of mechanical weathering in which rock is worn away by the grinding action of other rock particles is call

In 2002, the rare earth elements mine in mountain pass, california was closed because

The yearly amounts of carbon emissions from cars in belgium are normally distributed with a mean of 13.9 gigagrams per year and a standard deviation of 5.8 gigagrams per year. find the probability that the amount of carbon emissions from cars in belgium for a randomly selected year are between 11.5 gigagrams and 14.0 gigagrams per year. a. 0.340 b. 0.660 c. 0.167 d. 0.397