Which electron shell contains the valence electrons of a radium atom in the ground state?
(1) the sixth shell (2) the second shell
(3) the seventh shell (4) the eighteenth shell

(3) the seventh shell

Explanation:

Let's consider the electron configuration of radium in the ground state.

₈₈Ra: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s²

As we can see, the valence electrons are in the 7s shell, that is, the seventh shell. These are the electrons that participate in bonds.

fire could start, buildings collapsing, and ash falling from the sky.

explanation:

this is because the buildings or plants could catch on fire and the buildings would most likely collapse. lastly ash would fall because all the burning would cause ash to fall from the sky.

hope this .

cytokinesis is the splitting of a cell membrane to form 2 identical daughter cells. it's similar to mitosis as both cells have identical copies of dna and cytokinesis is a step in the mitotic cycle.