Question

The electron configuration for Helium (He) is shown below. 1s2 Which diagram shows the correct distribution of electrons in the electron shells of a helium atom?

Answer 1

:Fifth diagram shows the correct configuration.As Helium only has 2 electrons and therefore it possesses a configuration of 1s2.

Because the 1s orbital is full with 2 electrons and any additional electrons will have to go in a new energy level.

The electron configuration for Helium presents a full outer shell and is Helium is therefore termed as a Nobel Gas. Which means it will not react with other atoms.

Answer 2

Answer:

Ununseptium is called element 117 because it has 117 protons and 117 electrons. Elements with such a high number of protons are not found free in nature. The heaviest element that occurs in nature has 92 protons (uranium). Heavier elements are made in research settings by using nuclear reactions to add more protons.