11. What is the margin of safety? O A. The effect of a drug on the whole body
O B. A predictable but not desired response
O C. The difference between the therapeutic dose and the toxic dose
O D. The expected response that occurs from drug administration

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

characteristics of hydrocarbons