The original amount of radioactive substance is 10 grams. After several years, 2.5 gtams of the substance is remaining. How many half-lives havr passed since the mass of the subtance was 10 grams?

What is the mass of a steel cylinder that has a density of 75.0 g/mL and a volume of 12 mL? A. 6.25 g B. 900 g C. 87 g D. 63 g

Whitch is a type of mining where steam beds are minded

Use the partition function for a harmonic oscillator, q = 1 / (1 - e^-hv/kBT), to determine the ratio of populations in the lowest and first excited energy levels, P0/P1, for the indicated systems at two temperatures, 50 K and 298 K: (a) The 1700

A chemistry student needs of isopropenylbenzene for an experiment. He has available of a w/w solution of isopropenylbenzene in acetone. Calculate the mass of solution the student should use.

How many moles of NaCl are present in 530 ml of a 1.52m NaCl solution

Which organelles are unique to plant cells? chloroplasts mitochondria vacuoles nuclei

An atom that has 13 protons and 15 neutrons is an isotope of the element? How can I count it?

Which element is nuclear fusion least likely to produce? hydrogen, which has an approximate mass of 1 chlorine, which has an approximate mass of 35 argon, which has an approximate mass of 39 silicon, which has an approximate mass of 28 I know the

How deep does the surface current known as the Gulf Stream go A. 3,000 meters B. 3 meters C. 300 meters

What characteristics of a planet determine the strength of its gravitational force on other objects? A. diameter of the planet and its location in space B. the number of moons that the planet has C.