Final answer:
The atomic radius is a measure of an atom's size, the crystal structure refers to the arrangement of atoms in a crystal, electronegativity is a measure of an atom's ability to attract electrons, and the most common valence is the charge or number of electrons an atom gains, loses, or shares.
Step-by-step explanation:
Atomic Radius: The atomic radius is a measure of the size of an atom. It can be estimated from experimental techniques such as x-ray crystallography. Atomic radius generally decreases as you move from left to right across a period on the periodic table, and increases as you move down a group.
Crystal Structure: The crystal structure refers to the geometric arrangement of atoms in a crystal. Different elements can have different crystal structures, such as face-centered cubic (FCC), body-centered cubic (BCC), or simple cubic (SC). The crystal structure is determined by the size and arrangement of atoms in a solid.
Electronegativity: Electronegativity is a measure of an atom's ability to attract electrons in a chemical bond. It is expressed on the Pauling scale, and the values can be found on the periodic table. Electronegativity generally increases as you move from left to right across a period, and decreases as you move down a group.
Valence: The most common valence refers to the charge or number of electrons that an atom gains, loses, or shares to form a chemical bond. The most common valence can vary for different elements. For example, oxygen (O) typically has a valence of 2-, while sodium (Na) typically has a valence of 1+.