Question

the number of valence electrons that an atom has impacts its stability. stable atoms do not readily bond with other atoms to form new compounds. most elements on the periodic table are not stable enough to exist in nature as individual atoms. noble gases, the elements in group 18 of the periodic table, are the exception. atoms of noble gases are generally stable and unreactive. the bohr models of three noble gases are shown below. complete the sentences. helium has valence electrons, neon has valence electrons, and argon has valence electrons. all three noble gases have valence shell.

Explanation:

Step1: Analyze Helium's Bohr model

Helium has 2 electrons in its single - outer shell, so it has 2 valence electrons.

Step2: Analyze Neon's Bohr model

Neon has 8 electrons in its outermost shell, so it has 8 valence electrons.

Step3: Analyze Argon's Bohr model

Argon has 8 electrons in its outermost shell, so it has 8 valence electrons.

Step4: Determine the valence - shell state

Noble gases have a full valence shell. Helium has a full first shell (2 electrons is the maximum for the first shell), and neon and argon have a full outer shell with 8 electrons.

Answer:

Helium has 2 valence electrons, neon has 8 valence electrons, and argon has 8 valence electrons. All three noble gases have a full valence shell.