1. Aim: Determining ionization energy and electronegativity of elements
Do Now:
1. List in order of increasing atomic Radii:
Magnesium, Silicon, Barium, Bromine
2. Compare the Ionic Radius of Metals to their Atomic Radius, and the ionic radius of Nonmetals to their Atomic Radius

2. IOns
Positive and negative ions form when electrons are transferred between atoms.
Metals tend to lose electrons; nonmetals tend to gain those electrons

3. Anion
An ion with a negative charge
(N-3, O-2, Cl-1)

4. cation
An ion with a positive
charge
(Na+1, Ca+2)

5. Ionization energy
The energy required to remove an electron from an atom.
The larger the ionization energy value the harder to lose an electron (the stronger the atom is holding on to its electron)!

6. First ionization energy
The first ionization energy is the energy required to remove the first electron from its atom. (Table S)
First ionization energy tends to decrease from top to bottom within a group and increase from left to right across a period.

7. Second and Third Ionization Energy
The second ionization energy is the energy required to remove an electron from an ion with a 1+ charge.
The third ionization energy is the energy required to remove an electron from an ion with a 2+ charge.

8. Ionization Energy – Down a Group
Na has more energy levels (farther from protons) than Li making it easier to lose the outer electron.
As you move down a group or family the ionization energy decreases (easier to lose outer electron – more energy levels).

9. Ionization Energy – Across a Period
Both have the same number of energy levels, but Be has more protons pulling stronger on the outer most electron.
As you move across a period, the ionization energy increases (harder to lose outer electron – more protons).

11. Which has lowest ionization energy?
Chlorine
Sodium
Magnesium
Argon
1251 kJ/mol
496 kJ/mol
738 kJ/mol
1521 kJ/mol

12. Electronegativity
The ability of an atom to attract electrons when the atom is in a compound. (Table S)
The ability of an atom to steal an electron from another atom (electron thieves).

13. electronegativity
In general, electronegativity values decrease from top to bottom within a group, and increase from left to right across a period.

14. Electronegativity – Down a Group
Li has fewer levels than sodium making it easier for the protons in the nucleus to grab another atom’s electron.
As you move down a group or family the electronegativity decreases (harder to steal electrons – more energy levels).
The more energy levels act as a shield.

15. Electronegativity – Across a Period
Both have the same number of energy levels, but Be has more protons pulling stronger on another atom’s electron.
As you move across a period, the electronegativity increases (easier to steal electrons – more protons).
*Noble Gases do not have desire to steal electrons because of outer shell!*

17. Which has largest electronegativity?
Chlorine
Sodium
Magnesium
Argon
3.2
0.9
1.3 --

18. Trends (Atomic Radius Electronegativity Ionization Energy)

19. Regents Question 1
Which statement describes the general trends in electronegativity and metallic properties as the elements in Period 2 are considered in order of increasing atomic number? (1) Both electronegativity and metallic properties decrease. (2) Both electronegativity and metallic properties increase. (3) Electronegativity decreases and metallic properties increase. (4) Electronegativity increases and metallic properties decrease
Choice 4: electron negativity increases (heading to Fluorine)metallic character decreases you are leaving the metals

20. Regents Question 1
Which statement describes the general trends in electronegativity and first ionization energy as the elements in Period 3 are considered in order from Na to Cl? (1) Electronegativity increases, and first ionization energy decreases. (2) Electronegativity decreases, and first ionization energy decreases. (3) Electronegativity and first ionization energy both increase. (4) Electronegativity and first ionization energy both decrease.
Choice 3: Both ionization energy and electronegativity increase from left to right.

21. Regents Question 3
The amount of energy required to remove the outermost electron from a gaseous atom in the ground state is known as (1) first ionization energy (2) activation energy (3) conductivity (4) electronegativity
Choice 1: definition of ionization energy

22. Regents Question 4
Which term represents the attraction one atom has for the electrons in a bond from another atom?
(1) electronegativity
(2) electrical conductivity
(3) first ionization energy
(4) mechanical energy
Choice 1: Definition of electronegativity is the ability to attract an electron from another atom

23. Summary Define: Atomic Radius- Ionic Radius- Ionization Energy-
Electronegativity-