Which statement about elements is false? a. the same kind of atom exist in an element b. there are about 1000 elements found in nature c. some elements have been made in laboratories d. zinc, copper, and iron are elements

If 90.0 grams of ethane reacted with excess chlorine,how many grams of dicarbon hexachloride would form

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.

Which of the following natural processes is most likely to support the formation of an underwater sinkhole? a pollution buildup from deposited minerals b limestone cave collapsing due to changes in sea level c erosion of large amounts of sand moved by ocean waves d oxidation of rock formed by chemical weathering