A radioactive substance has a half-life period of 30 days. Calculate the time required for three- fourths of the original number of atoms to disintegrate. A. 60 days
B. 12 days
C.90 days
D. 30 days

Calculate the number of moles of ethane in 100 grams

Acompound has a molar mass of 92.02 grams/mole, and its percent composition is 30.4% nitrogen (n) and 69.6% oxygen (o). what is its molecular formula? a. n2o4 b. no2 c. n2o d. n4o2

Plz ill give u brainliest which of the following steps is not likely to take place during cellular respiration? a.oxygen combines with carbon of simple sugar. b. energy molecule transfers energy to cells. d. energy is used up.