The answer is c because five plus two is seven and take away that is 4
Answer:
Mineral dusts are solid particles, that may become airborne depending upon their origin and the surrounding physical conditions. Lead is potential poison. It is obtained from the earth crust. The lead poisoning is a popular occupational hazard. The lead in air, when taken by the human body through respiration is responsible to cause anemia, weakness and kidney and brain damage, labored breathing and lung diseases.
We are given with the percentage composition of oxygen in an oxide from phosphorus and oxygen equal to 43.6 percent. that is the phosphorus is equal to 56.4 percent. we divide each with the molar mass and divide each with the smaller quantity. P then is equal to 1 and O is equal to 1.5. In this case, the empirical formula is P2O3.