In May 212, it was revealed on the Internet that many pharmaceutical companies used recycled waste leather shoes to make drug capsules. Because leather products contain chromium (Cr),

A, according to the information obtained in one cell of the periodic table of elements, it is known that the atomic number of chromium is 24, and from the atomic number = the number of protons in the nucleus, it is known that there are 24 protons in this chromium nucleus, so the option statement is correct.

b, according to the information obtained in one cell of the periodic table of elements, the name of this element is chromium, with "?" beside it, which belongs to a metal element, so it is correct. Therefore, the option statement is wrong.

D. According to the information obtained in a cell in the periodic table, it can be known that the atomic number of chromium element is 24, and there are 24 electrons outside the nucleus of chromium element from the atomic number = the number of electrons outside the nucleus, so the option statement is correct.

Therefore, C.