840.5 ppm = 840,500 ppb
| ppm | ppb |
|---|---|
| 825.5 ppm | 825,500 |
| 830.5 ppm | 830,500 |
| 835.5 ppm | 835,500 |
| 840.5 ppm | 840,500 |
| 845.5 ppm | 845,500 |
| 850.5 ppm | 850,500 |
| 855.5 ppm | 855,500 |
840.5 ppm = 840,500 ppb
1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm