Find similarities and differences between: a) a calcium atom and a calcium ion; b) an oxygen atom and an oxygen ion.

a) a calcium atom and a calcium ion;
Similarities: the structure of the atomic nucleus (charge of the atomic nucleus (+20), the number of protons (20), the number of neutrons (40-20 = 20))
Differences: 1. The structure of the electron shell (the total number of electrons (in the calcium atom 20, and in the calcium ion 18), the number of energy levels, or layers, of the electron shell of the atom (in the calcium atom 4, and in the calcium ion 3), the number of electrons per outer layer (in the calcium atom 2, and in the calcium ion – 8 (is complete)) 2. The calcium atom is an electrically neutral particle (Ca0), and the calcium ion is a charged particle (Ca2 +).
b) an oxygen atom and an oxygen ion.
Similarities: the structure of the atomic nucleus (the charge of the atomic nucleus (+8), the number of protons (8), the number of neutrons (16-8 = 8)), the number of energy levels, or layers, of the electron shell of the atom (2).
Differences: 1. The structure of the electron shell (the total number of electrons (in the oxygen atom 8, and in the oxygen ion 10), the number of electrons on the outer layer (in the oxygen atom 6, and in the oxygen ion – 8 (is complete)). 2. Atom oxygen is an electrically neutral particle (O0), and an oxygen ion is a charged particle (O2-).

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