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What element is this? How do you know? (Page 495 and Periodic Table Pages 500-501)

What element is this? How do you know? (Page 495 and Periodic Table Pages 500-501)-example-1
User Mady
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What does the question look like?
User Elias Meireles
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Answer:

This element is Helium (He).

Step-by-step explanation:

The figure above shows an element with 2 electrons, 2 protons and 2 neutrons. The only element that has these characteristics is Helium, and all of this can be confirmed if you look for helium in the periodic table.

The helium element is a noble gas, belonging to the family 0 or 8A of the periodic table, is inert, ie, does not undergo chemical reaction, follows the rule of the duet (is stable with 2 electrons in its last valence layer), has 8 isotopes, but practically negligible, since about 99.999% of helium is the stable isotope 4He. It is colorless and odorless has an atomic number 2 and an electronic configuration of 1s2, atomic mass 4,002 u, its chemical symbol is He, its melting point is -272,2 ° C and boiling point -268,9 ° C, even near the Absolute zero gas does not solidify, it just forms unstable diatomic molecules.

User Bspoel
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