Hydrogen wants to obtain one electron to achieve a stable electron configuration similar to the noble gas helium.
Calcium loses two electrons to obtain a noble-gas electron configuration.
Chlorine atom has 17 electrons. It is readily accepting an electron from another atom to obtain its stable electron configuration (of argon). A chloride ion has 18 electrons.
You can achieve a stable electron configuration by using two electrons by forming a covalent bond with another atom that also has two valence electrons. In this way, each atom can share its valence electrons to achieve a full outer shell and achieve stability.
Sulfur gains two electrons to attain a noble gas configuration, which is the electron configuration of argon. This allows sulfur to have a stable octet of electrons in its outer shell and achieve a more stable electron configuration.
Phosphorus, like all atoms, tries to achieve a full electron shell. For Phosphorus to achieve its full shell and obtain an electron configuration that is isoelectronic with Argon, it must gain 3 electrons. Therefore, Phosphorus forms a -3 anion.
Hydrogen wants to obtain one electron to achieve a stable electron configuration similar to the noble gas helium.
Calcium loses two electrons to obtain a noble-gas electron configuration.
Ionic compounds obtain a stable electron configuration by transferring electrons from one atom to another to achieve a full outer shell. This transfer of electrons results in the formation of positive and negative ions that are attracted to each other by electrostatic forces, creating a stable compound.
Chlorine atom has 17 electrons. It is readily accepting an electron from another atom to obtain its stable electron configuration (of argon). A chloride ion has 18 electrons.
You can achieve a stable electron configuration by using two electrons by forming a covalent bond with another atom that also has two valence electrons. In this way, each atom can share its valence electrons to achieve a full outer shell and achieve stability.
Sulfur gains two electrons to attain a noble gas configuration, which is the electron configuration of argon. This allows sulfur to have a stable octet of electrons in its outer shell and achieve a more stable electron configuration.
Carbon needs to gain four electrons in order to obtain a noble gas electron configuration, similar to that of neon. This will result in a full valence shell with eight electrons, fulfilling the octet rule.
The outermost shell in an atom is also known as the valence shell. When an atom is able to donate or obtain electrons to obtain a noble gas electron configuration, it is said to be stable. Generally, metals are electron donors and non metals are electron acceptors.
metals lose electrons to form ions so as to obtain noble gas configuration. for e.g. sodium(Na) has 11 electrons i.e. 1 electron in its valent (last) shell, to attain noble gas configuration sodium loses 1 electron which may be gained by a non-metal to stabilize itself.
Potassium (K) can achieve eight valence electrons by losing one electron to form a stable cation with a +1 charge. In this form, it will have the same electron configuration as the nearest noble gas (argon), which has a full valence shell with eight electrons.
In the modern periodic table, these elements belong to group 17. These elements have s2 p5 electron configuration. Hence they need one more electron from an electron donor to fulfill its valence shell to obtain noble gas configuration.The elements in the group 7A has 7 electrons in their outermost energy level. They gain 1 electron to get the noble gas configuration. The elements in the group 7A are called halogens.