AP Chem

Why does an ion of phosphorus, P3-, have a larger radius than a neutral atom f phosphorus.

The electrons in P-3 have a greater coulombic repulsion than those in a neutral atom.

Coulombic attraction

the attraction between oppositely charged particles

Nuclear Charge and their relationship between atomic radius

Higher nuclear charge pulls electrons closer, making atomic size smaller. Lower nuclear charge means weaker pull, so atomic size is larger.

Ionization energy and atomic radius

As atomic radius increases → ionization energy decreases.

As atomic radius decreases → ionization energy increases.

Electron Shielding and atomic radius

More electron shielding → larger atomic radius.

Electronegativity and atomic radius

Smaller atomic radius → higher electronegativity.

Larger atomic radius → lower electronegativity.

Ionization Energy Trend

(What happens across a period and down a group?)

Across a period → Increases (nuclear charge pulls electrons tighter)

Down a group → Decreases (electrons farther from nucleus, easier to remove)

Ex: Potassium has a lower ionization energy than Cl and Ar because its outer electron is farther from the nucleus!

Which ejected electrons have highest velocity?

Least tightly bound = highest velocity

Outer subshells (e.g., 3p for chlorine) eject fastest electrons!

Molar mass of carbon = ?

Molar mass (g/mol) = Atomic mass (amu)

1 mole = 6.022 × 10²³ atoms

Carbon: ~12.01 g/mol = ~12.01 amu/atom

Compare sodium vs chlorine — trends?

Cl: higher electronegativity & ionization energy

Na: larger atomic radius

What can be inferred from examining mass spectroscopy

The existence of isotopes

In general, do metals or non metals from the same period have higher ionization energies? Why?

Nonmetals have higher ionization energies because they are closer to having filled a complete energy level.

Nitrogen’s electronegativity value is between those of phosphorus and oxygen.

The value of nitrogen is greater than that of phosphorus because nitrogen is smaller but less than that of oxygen because nitrogen has a smaller effective nuclear energy.

Most transition metals share a common oxidation state of 2+

Transition metals will lose their outermost s-block electrons when forming bonds.

Ionization Energy

Ionization energy is the energy required to remove an electron from an atom. Ionization energy increases to the right and decreases downward on the periodic table. Ionization energy increases with the number of electrons removed.

Nitrogen's electronegativity value is between those of phosphorus and oxygen. What statement best supports this.

› The value for nitrogen is greater than that of phosphorus because nitrogen is smaller but less than that of oxygen because of its nuclear charge.

Most transition metals share a common oxidation state of +2. Which of the following best explains why?

Transition metals will lose their outermost s-block electrons when forming