Which is true about a chemical reaction
A. a substance always changes in color, shape, and/or size

B. a substance always changes temperature

C. a substance only undergoes a physical change

D. a new substance with different chemical properties formed

The reactions shown here can be combined to make the overall reaction c(s) + h2o(g) ⇌ co(g) + h2(g) by reversing some and/or dividing all the coefficients by a number. a. c(s) + o2(g) → co2(g) k=1.363×10^69 b. 2 h2(g) + o2(g) → 2 h2o(g) k=1.389×10^80 c. 2co(g) + o2 (g) → 2 co2(g) k=1.477×10^90

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

Why does a plastic bottle that is sealed at a high altitude change it’s shape when taken to lower altitude