Which of the following statements are true? 1. Selenium (Se) has the electron configuration [Ar]4s 2 4d 10 4p 3 . 2. Silver (Ag) has the electron configuration [Kr]5s 1 4d 10 . 3. Chromium (Cr) has the electron configuration [Ar]4s 1 3d 5 .

2. Atoms and the Periodic Table - Part 3 of 3

2. Atoms and the Periodic Table / The Electron Configuration: Exceptions (Simplified) / Problem 5

Which of the following statements are true?
1. Selenium (Se) has the electron configuration [Ar]4s²4d¹⁰4p³.
2. Silver (Ag) has the electron configuration [Kr]5s¹4d¹⁰.
3. Chromium (Cr) has the electron configuration [Ar]4s¹3d⁵.

1 only

2 only

3 only

1 and 2 only

2 and 3 only

1 and 3 only