144. Задачка по химии №014 4415
1.1 The mass concentration of flour dust in the air of the working areas of the premises of flour mills is 4.2 mg / m3. Determine the numerical concentration of flour dust if the average particle diameter is 3.7 μm and their density is 1.1 * 103 kg / m3.
Оплата и выдача товара осуществляются через партнёрскую платформу.