Rank the following atoms from highest to lowets energy: Ca, Be, Ba, C
To rank the atoms from highest to lowest energy, we need to consider the electron configuration of each atom. The energy of an atom is primarily determined by the arrangement and distribution of its electrons.
1. Let's start with the highest energy atom:
- Carbon (C) has an atomic number of 6, meaning it has 6 electrons. Its electron configuration is 1s² 2s² 2p². The valence electrons (outermost electrons) are in the 2p subshell, which is higher in energy than the 2s subshell.
2. Moving onto the next atom with relatively high energy:
- Beryllium (Be) has an atomic number of 4, with an electron configuration of 1s² 2s². Although Be also has valence electrons in the 2s subshell like Carbon, Carbon's 2p subshell is energetically higher than the 2s subshell.
3. Now, let's consider the lower energy atoms:
- Calcium (Ca) has an atomic number of 20, with an electron configuration of 1s² 2s² 2p⁶ 3s² 3p⁶ 4s². As compared to Carbon and Beryllium, Calcium has multiple full energy level shells preceding its valence electrons, making it lower in energy than the previous two atoms.
4. Finally, the lowest energy atom:
- Barium (Ba) has an atomic number of 56, with an electron configuration of 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s². Barium has an electron configuration with progressively more filled energy levels than the previous atoms, indicating a lower energy state.
Therefore, the ranking from highest to lowest energy is: C (Carbon) > Be (Beryllium) > Ca (Calcium) > Ba (Barium).