Question
Robert Parr and Ralph Pearson's original definition of this quantity in a 1983 paper included a coefficient of one-half. For 10 points each:
[10h] Name this quantity proportional to the second derivative of energy with respect to electron number.
ANSWER: chemical hardness [or absolute hardness]
[10e] Hard-soft acid-base theory extends the acid-base theory named for this American chemist, who defined acids as electron pair acceptors and bases as electron pair donors.
ANSWER: Gilbert Lewis [Gilbert Newton Lewis; or Lewis acid-base theory; or Lewis acids; or Lewis bases]
[10m] Chemical hardness is proportional to the difference between ionization energy and this quantity. Mulliken electronegativity, which is closely related to chemical hardness, is proportional to the sum of ionization energy and this quantity.
ANSWER: electron affinity
<Joseph Krol , Science - Chemistry - Inorganic>
Summary
| 2023 NASAT | 06/17/2023 | Y | 8 | 16.25 | 100% | 63% | 0% |
Data
| Kentucky B | California | 0 | 10 | 0 | 10 |
| Illinois White | Maryland Gold | 0 | 10 | 0 | 10 |
| Maryland Red | Asia A | 0 | 10 | 10 | 20 |
| Missouri B | Kentucky A | 0 | 10 | 10 | 20 |
| Missouri A | New Jersey A | 0 | 10 | 10 | 20 |
| Arkansas | New Jersey B | 0 | 10 | 0 | 10 |
| Illinois Blue | Pennsylvania | 0 | 10 | 10 | 20 |
| Asia B | Virginia | 0 | 10 | 10 | 20 |