What is the definition of half-life?

Which of the following would not diffuse through the plasma membrane by means of simple diffusion? 1 oxygen 2 glucose 3 a steroid hormone 4 a lipid soluble vitamin

The lattice enthalpy (formation of ionic solid from ions in the gas phase) for agcl(s) is -916 kj/mol and the hydration enthalpy (dissolution of gaseous ions into water) is -850 kj/mol. how much heat (in joules) is involved in forming 1l of saturated agcl solution (1.8 × 10-4 g / 100 ml water) by dissolving agcl(s)? assume solution volume does not change much upon dissolution. the equations are given below. ag+(g) + cl−(g) æ agcl(s)

What prefix multiplier is appropriate for reporting a measurement of 5.57 ×10−5 m?