Which of the following could indicate that a chemical change has taken place?

gas formation

formation of a precipitate

color change

all of the above

Which one of the following elements will combine with chlorine in a 12 ratio to give a formula of XCI2.? Na AL Mg F c

Which of the following describes the contribution of Eratosthenes? A. discovery of the geocentric theory B. discovery of a mathematical formula to relate the sides of a right triangle C.

Your BAC level depends on

What role does sea water play in the water cycle?

What's the name of the process that occurs as the dry ice undergoes a phase change in the flask

True or false forensic technicians receive OSHA data sheets regarding toxic chemicals they deal with in their lab.

What did robert boyle believe about atoms

Where do most carbon monoxide emissions come from?

The osmotic pressure exerted by a solution is equal to the molarity multiplied by the absolute temperature and the gas constant RSuppose the osmotic pressure of a certain solution is measured to be 22. atm at an absolute temperature of 353.

Which one of the following is a redox reaction?. 2 Na (g) + Cl2 (g) 2 NaCl (s) A. K2Cr2O7 (aq) + 2 KOH (aq) 2 K2CrO4 (aq) + H2O (l) B. H2O (l) H + (aq) + OH - (aq) C. Na2CO3 (s) + 2 HCl (aq) 2 NaCl (aq) + CO2 (g) + H2O (l) D.