The half-life for beta decay of strontium-90 is 28.8 years. A milk sample is found to contain 10.0 ppmstrontium-90. How many years would pass before the strontium-90 concentration would drop to 1.25 ppm? Group of answer choices

Infants born with severe respiratory problems are sometimes given liquid ventilation: they breathe a liquid that can dissolve more oxygen than air can hold. one of these liquids is a fluorinated compound, cf3(cf2)7br. the solubility of oxygen in this liquid is 66 mlo2 per 100 ml liquid. in contrast, air is 21 % oxygen by volume. calculate the moles of o2 present in an infant's lungs (volume: 12 ml ) if the infant takes a full breath of air. assume a pressure of 1 atm in the lungs.

What are the genotypic and phenotypic ratios

List four observations that indicate that a chemical reaction may be taking place