Which of these represents a chemical change?

What happens to energy over the course of a reaction?

The rate constant for the second-order reaction 2no2 (g) ? 2no (g) o2 (g) is 0.540 / (m · s) at 300°c. how long (in seconds) would it take for the concentration of no2 to decrease from 0.500 m to 0.250 m

Which of the following pairs of objects could have a magnetic force acting between them? A. A block of wood and a metal spoon B. Two metal spoons C. Two blocks of wood D. A metal spoon and a glass cup

Snape grows tired of these conceptual questions and thinks it's time for a problem. What is the retention factor if the distance travelled by the solvent front is 2.00 cm, and the distance travelled by the ion is 0.40 cm?

Which of the following compounds is soluble in water? A. lead (II) nitrate B. iron (II) oxide C. zinc hydroxide D. silver carbonate

What phase change is endothermic

A Gran plot for a potentiometric titration resulted in a slope of 5.56 x 105. Measurements were made using SCE as the reference electrode and the analyte Eo was determined to be 0.354 V.

Aight imma let you guys i

In which choice is the ellipsis used correctly to select from this sentence from The Scarlet Letter? A throng of bearded men, in sad-coloured garments and grey steeple-crowned hats, inter-mixed with women, some wearing hoods, and others bareheaded,

Explain the difference between the greenhouse effect and global warming.