You want to prepare 5.0 liters of a 425 ppb Li 1 solution. How many grams of LiCO3 do you need to weigh out to dissolve in the 5.0 liters?
If you had started with a 5000. ppm solution of Li2CO3 solution, how many mL of it would you need to pipet into the 5.0 liter to achieve the same 425 ppb Li 1 solution?