The correct answer is C. Magnetic domains must come in pairs one north one south. I took the test.
54. fluorine
55. oxygen
56. they have the same number of protons
57. nucleus 3
Explanation:
54. The element represented by the nucleus 1 have 9 protons and 9 neutrons. The atomic number of the element is equal to the number of protons = 9, so the element is fluorine.
55. The element represented by the nucleus 2 have 8 protons and 10 neutrons. The atomic number of the element is equal to the number of protons = 8, so the element is oxygen.
56. nucleus 2 contains 8 protons and 10 neutrons
nucleus 4 contains 8 protons and 11 neutrons.
The atoms that have the same number of protons but different number of neutrons are called isotopes.
57. nucleus 3 have 10 protons and 10 neutrons and correspond to neon. Neon have 10 electrons (equal to the number of protons) and have the electronic configuration 1s² 2s² 2p⁸. Because all the electrons shells are filled with electrons, neon have a stable electron configuration.
Learn more about:
subatomic particles
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