Question

________ is isoelectronic with helium. ________ is isoelectronic with helium. li- b4+ be mg2+ b3+

Answer 1

$\boxed{{{\text{B}}^{3+}}}$ is isoelectronic with helium.

Further explanation:

Isoelectronic species:

Atoms, molecules or any other species that contain the same number of electrons are isoelectronic species. These differ in their chemical and physical properties. For example, ${\text{N}}{{\text{a}}^+}$ and ${\text{M}}{{\text{g}}^{2+}}$ both have ten electrons in them and therefore called isoelectronic species.

The atomic number of helium is 2. So it has 2 protons in it. Since it is a neutral atom, it will also contain 2 electrons in it.

The atomic number of lithium is 3. So its neutral atom has 3 electrons. But ${\text{L}}{{\text{i}}^-}$ is formed by the gain of one electron and therefore the total number of electrons in ${\text{L}}{{\text{i}}^-}$

becomes 4.

The atomic number of boron is 5. So its neutral atom has 5 electrons. But ${{\text{B}}^{4+}}$ is formed by the loss of four electrons and therefore the total number of electrons in ${{\text{B}}^{4+}}$ becomes 1.

The atomic number of beryllium is 4. So it has 4 protons in it. Since it is a neutral atom, it will also contain 4 electrons in it.

The atomic number of magnesium is 12. So its neutral atom has 12 electrons. But ${\text{M}}{{\text{g}}^{2+}}$ is formed by the loss of two electrons and therefore the total number of electrons in ${\text{M}}{{\text{g}}^{2+}}$ becomes 10.

The atomic number of boron is 5. So its neutral atom has 5 electrons. But ${{\text{B}}^{3+}}$ is formed by the loss of three electrons and therefore the total number of electrons in ${{\text{B}}^{3+}}$

becomes 2.

The number of electrons in helium and ${{\text{B}}^{3+}}$ is 2 and therefore both are isoelectronic species.

Learn more:

1. The ions of which element have same electrons as that of given noble gas? brainly.com/question/2193397

2. Write the atomic number, atomic mass and net charge of ion of iron: brainly.com/question/2158589

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Structure of the atom

Keywords: helium, Mg2+, B3+, B4+, Be, Li-, isoelectronic species, electrons, atomic number, atoms, molecules, ions, gain loss, 2, 10, 4, 1.

Answer 2

B3+ is isoelectronic with helium.
Isoelectronicity is the phenomenon whereby two or more molecular entities have the same number of electrons or similar electronic configuration regardless of the nature of the elements that are involved.
In the question given above, helium and B3+ have the same number of electrons. Helium has two electrons. Boron has five electrons but it has given away three of the electrons [that is why it has a charge of +3] and it now has only two left.