1. **Problem Statement:** Convert the given units as requested in each question. 2. **Conversion formulas and rules:** - To convert grams per milliliter (g/mL) to grams per liter (g/L), multiply by 1000 because 1 L = 1000 mL. - To convert meters per second (m/s) to kilometers per hour (km/h), multiply by 3.6 because 1 m/s = 3.6 km/h. - To convert milliliters (mL) to liters (L), divide by 1000 because 1 L = 1000 mL. - To convert micrometers (µm) to kilometers (km), divide by $10^9$ because 1 km = $10^9$ µm. - To convert kilometers (km) to micrometers (µm), multiply by $10^9$. 3. **Step-by-step conversions:** **(a) Convert 1.31 g/mL to g/L:** $$1.31\ \text{g/mL} \times 1000 = 1310\ \text{g/L}$$ **(b) Convert 35 m/s to km/h:** $$35\ \text{m/s} \times 3.6 = 126\ \text{km/h}$$ **(c) Convert 21.11 mL to L:** $$21.11\ \text{mL} \div 1000 = 0.02111\ \text{L}$$ **(d) Convert 10 µm to km:** $$10\ \mu\text{m} \div 10^9 = 1.0 \times 10^{-8}\ \text{km}$$ **(e) Convert 1 km to µm:** $$1\ \text{km} \times 10^9 = 1,000,000,000\ \mu\text{m}$$ 4. **Summary:** - 1.31 g/mL = 1310 g/L - 35 m/s = 126 km/h - 21.11 mL = 0.02111 L - 10 µm = $1.0 \times 10^{-8}$ km - 1 km = 1,000,000,000 µm These conversions use basic unit relationships and multiplication or division by powers of ten or conversion factors.