A substance which is made up of identical atoms is a (n):

chemical

element

compound

alloy

Why is photosynthesis a chemical change?

A coal-fired power plant emitshot gases at a rate of 50 ft3/sec. The hot gas contains flyash, which is emitted at a rate of 120 lb of flyash per hour. What is the concentration of flyash in micrograms per cubic meter?

If 5 moles of Fe2O3 react with excess CO, what is the maximum amount of age and CO2 that can be formed?

Which of the following would most likely cause a building to erode? A. acid rain B. the heat island effect C. heat pollution D. vehicle emissions

In an experiment, 3.25 g of NH3 are allowed to react with 3.50 g of O2. 4NH3 + 5O2 > 4NO + 6H2O a. Which reactant is the limiting reagent? O2 b. How many grams of NO are formed

Which formula correctly represents the product of an addition reaction between ethene and chlorine?

Compare gases with liquids and solids according to the kinetic molecular theory

4Cr (s) + 3O2 (g) = Cr2O3 (s) Find the theoretical yield in moles and grams

Which isotope is used to date ancient artifacts such as fossils?

Bromine + calcium iodide  calcium bromide + iodine