Answer:
Student 4
Step-by-step explanation:
In the structure of the atom of an element, there are protons, electrons and neutrons. The number of protons in the atom of such element determines the atomic number of the element. For example, if Calcium contains 20 protons, the atomic no of Calcium will be 20. Since this is so, it means that the identity of an element on the periodic table can be known using the number of protons/atomic no.
According to this question, four students are gathering information on elements to determine their identity. Based on the explanation above, it takes only the number of protons = atomic no. of the element to identify it. Hence, student 4, who counts the number of protons will correctly identify the element using his/her data.