Answer:
The element that has a valence configuration of 6s1 is option (a) K (potassium).
Step-by-step explanation:
The electron configuration of an element describes how electrons are arranged in its atomic orbitals. The notation used to represent electron configuration follows a specific pattern. The first number represents the principal energy level (n), followed by the letter representing the type of orbital (s, p, d, f), and finally, the superscript denotes the number of electrons in that orbital.
In this case, the valence configuration is described as 6s1. The "6" indicates the principal energy level or shell (n = 6), and the "s" refers to the s orbital. The superscript "1" indicates that there is only one electron in the 6s orbital.
The options given are K (potassium), Rb (rubidium), Na (sodium), Cs (cesium), and Li (lithium). We need to determine which of these elements has an electron configuration that matches 6s1.
Among the options, only potassium (K) has an electron configuration of [Ar] 4s1, which corresponds to 6s1 after considering the previous energy levels. The noble gas abbreviation [Ar] indicates that the electron configuration of potassium is similar to that of argon (Ar) with a completed 3rd energy level. Following argon, the 4th energy level starts with the 4s orbital, and potassium has one electron in that orbital.
Therefore, the element with a valence configuration of 6s1 is potassium (K), option (a).
Please feel free to download and use my periodic table which has the orbital numbers along the sides and in some element blocks.