1. Chapter 6 Section 3
Periodic Trends

2. Atomic Radius
Many properties of elements tend to change in a predictable way.
Atomic Size is one of those properties.
In general, there is an increases in atomic radius as you move from right to left across a period.
Also, there is an increase in atomic radius as you move down a group.

3. Atomic Radius

4. Ionic Radius
A quick note about ions: Atoms can gain or lose electrons to form ions.
An ion is an atom or a bonded group of atoms that has a positive or negative charge.
When atoms lose electrons and form positive ions, they become smaller.
When atoms gain electrons and form negative ions, they become larger.

5. Ionization Energy
To form a positive ion, an electron must be removed from a neutral atom. This requires energy.
The energy is needed to overcome the attraction between the positive charge of the nucleus and the negative charge of the electron.
Ionization energy is defined as the energy required to remove an electron from a gaseous atom.

6. Ionization Energy
Think of ionization energy as how strongly an atom’s nucleus holds onto its electrons.
High ionization energy indicates the atom has a strong hold on its electrons.
These atoms will be less likely to form positive ions.

7. Ionization Energy
Low ionization energy indicates the atom loses its electrons easily.
These atoms are likely to form positive ions.
After removing the first electron, it is possible to remove another. This is known as the second ionization energy.

8. Ionization Energy
Ionization energy generally increases as you move from left to right across a period.
Ionization energy generally increase as you move up a group.

9. Ionization Energy

10. Electronegativity
The electronegativity of an element indicates the relative ability of its atoms to attract electrons in a chemical bond.
Electronegativity generally increases as you move up a group.
Also, electronegativity generally increases as you move left to right across a period.

11. Electronegativity