Question

Which of the following elements has the smallest atomic number?

1.Scandium, which has twenty-one protons
2.Sulfur, which has sixteen protons
3.Lithium, which has three protons
4.Helium, which has two protons

Answer 1

Helium, with two protons, has the smallest atomic number among the elements provided.

Step-by-step explanation:

The atomic number of an element corresponds to the number of protons found in the nucleus of its atoms, and it determines the element's identity. The student has provided the atomic numbers of several elements directly by indicating the number of protons each has. Among the options given, helium, with two protons, has the smallest atomic number, which makes it the element with the fewest protons compared to scandium with twenty-one protons, sulfur with sixteen protons, and lithium with three protons. Hence, helium with an atomic number of 2 is the correct answer.