Question: atomic radius

Answer: "one half of the distance between the nuclei of two atoms of the same element when the atoms are joined"

Question: ion

Answer: "an atom or group of atoms that has a positive or negative charge. "

Question: cation

Answer: "An ion with a positive charge is called a cation. The charge for a cation is written as a number followed by a plus sign."

Question: anion

Answer: An ion with a negative charge is called an anion. The charge for an anion is written as a number followed by a minus sign.

Question: ionization energy

Answer: "The energy required to remove an electron from an atom is called ionization energy. This energy is measured when an element is in its gaseous state."

Question: electronegativity

Answer: "ability of an atom of an element to attract electrons when the atom is in a compound. Scientists use factors such as ionization energy to calculate values for electronegativity"

Question: What are the trends among the elements for atomic size?

Answer: "general, atomic size increases from top to bottom within a group and decreases from left to right across a period"

Question: How do ions form?

Answer: "Positive and negative ions form when electrons are transferred between atoms"

Question: What are the trends among the elements for first ionization energy, ionic size, and electronegativity?

Answer: "First ionization energy tends to decrease from top to bottom within a group and increase from left to right across a period"

Question: 18. How does atomic size change within groups and across periods?

Answer: "atomic size increases from top to bottom within a group and decreases from left to right across a period.

Question: 19. When do ions form?

Answer: When electrons are transferred between atoms

Question: 20. How do first ionization energies vary within groups and across periods?

Answer: decreasey from top to bottom within a group and increase from left to right across a period

Question: 21. Compare the size of ions to the size of the atoms from which they form.

Answer: "Cations are always smaller than the atoms from which they form. Anions are always larger than the atoms from which they form"

Question: 22. How do electronegativity values vary within groups and across periods

Answer: "decrease from top to bottom within a group. For representative elements, the values tend to increase from left to right across a period."