A patient is prescribed 50 millimoles of magnesium ions to be given by intravenous injection. The magnesium sulfate is supplied as a 40% w/v solution and it must be diluted to 200 mg/mL prior to administration. Extra information: Magnesium sulfate 1 g is equivalent to approximately 4 millimoles Mg2+ What is the volume of 40% w/v solution required?

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.