Which of the following statements is true?

boiling and melting points are chemical properties.
a molecule of oxygen can have atoms of carbon in it.
elements are substances made of only one type of atom.
the number of electron shells in an atom is called the atomic number.

Elements are substances made of only one type of atom is true,

he uptake of drugs from the intestine is often strongly influenced by diffusion. for example, consider a water-insoluble steroid for treating inflammation that is solubilized in aggregates of detergent molecules, called micelles. these micelles, aggregates of 80 soap molecules, have a molecular weight of 24,000, a diameter of 2.6 nm, and a charge of -27. the positively charge ions (counterions) in this system are na".