This is not a valid conversion. Milliliters (mL or ml) and liters (L) are measures of volume. Grams (g), kilograms (kg) and milligrams (mg) are measures of weight or mass.
300 grams of water is 300 ml.
This is not a proper conversion. Milliliters (mL or ml) and liters (L) are measures of volume. Grams (g), kilograms (kg) and milligrams (mg) are measures of weight or mass.
Milligrams and milliliters are two different measures, milligrams measure mass and milliliters measure volume and you can not convert one to the other.
This is not a valid conversion; milligrams (mg) and grams (g) are measures of weight or mass while milliliters (mL or ml) measure volume.
Milligrams and milliliters measure different things (milligrams measure mass and milliliters measure volume), so there is no universal conversion factor. For example, 300 mg of air takes up about 250 ml, whereas 300 mg of water takes up only 0.3 ml. To get an answer you need to specify what substance you are measuring, or, if the substance is in solution, you need to specify the concentration of the solution.
This is not a valid conversion. Milliliters (mL or ml) and liters (L) are measures of volume. Grams (g), kilograms (kg) and milligrams (mg) are measures of weight or mass.
This cannot be sensibly answered. A milliliter (mL or ml) is a measure of volume, grams (g), kilograms (kg) and milligrams (mg) are measures of weight or mass.
This cannot be sensibly answered. Milliliters (mL or ml) is a measure of volume, milligrams is a measure of weight or mass.
12.5mg
This is not a valid comparison; milligrams (mg) is a measure of weight or mass while milliliters (mL or ml) measure volume.
This cannot be sensibly answered. A milliliter (mL or ml) is a measure of volume, grams and milligrams are measures of weight or mass.
That completely depends on the density of the substance in the 1.2 ml. If the 1.2 ml is empty, then there are no milligrams in it at all.