Our day is 24 hours long because that is the time it takes the earth to

Write the complete balanced equation for the reaction between lead (iv) oxide (pbo2) and water (h2o).

Which of the following is an indication that a substance has undergone a chemical change? a. no new product has been formed. b. the color of the substance has not changed. c. the original constitute has not changed. d. the molecular structure has changed.

Anurse used a 0.02-mg/l solution of disinfection to clean a patients wound. what is the concentration of the solution expressed as a percentage?