No, atomic radius and atomic number are not the same thing. They are two different concepts related to atoms.
Atomic number: The atomic number of an atom represents the number of protons in the nucleus of an atom. It uniquely identifies an element and determines its position in the periodic table. For example, hydrogen has an atomic number of 1, indicating that it has one proton in its nucleus. Atomic numbers are whole numbers and are assigned sequentially to elements based on the number of protons.
Atomic radius: The atomic radius refers to the size of an atom. It is a measure of the distance from the nucleus to the outermost electron shell of an atom. Since electrons do not have definite orbits but exist in probability distributions called atomic orbitals, the concept of atomic radius is more nuanced. However, atomic radius is often defined as half the distance between the nuclei of two adjacent atoms in a solid crystal lattice.
Atomic radius can vary depending on the element and its chemical environment. It generally decreases across a period (horizontal row) in the periodic table from left to right due to increasing nuclear charge and effective attraction on the electrons. However, atomic radius generally increases down a group (vertical column) due to the addition of electron shells.
In summary, atomic number represents the number of protons in an atom's nucleus, while atomic radius refers to the size of an atom.