It should lose two electrons
The noble gas configuration for Sr (strontium) is [Kr]5s2
Iodine accepts one electron to achieve noble gas configuration. Strontium loses two electrons to achieve noble gas configuration. Nitrogen accepts three electrons to achieve noble gas configuration. Krypton already has a noble gas configuration.
Selenium should gain two electrons and lose six electrons to achieve a noble gas electron configuration.
Calcium loses two electrons to obtain a noble-gas electron configuration.
Aluminum needs to lose 3 electrons to gain a noble gas electron configuration.
2
The bipositive ion of strontium takes the electron configuration of xenon.
The noble gas configuration for Sr (strontium) is [Kr]5s2
Iodine accepts one electron to achieve noble gas configuration. Strontium loses two electrons to achieve noble gas configuration. Nitrogen accepts three electrons to achieve noble gas configuration. Krypton already has a noble gas configuration.
The noble gas configuration of strontium is [Kr]5s2.
Losing an electron cesium has a noble gas configuration.
Two electrons
Selenium should gain two electrons and lose six electrons to achieve a noble gas electron configuration.
Calcium loses two electrons to obtain a noble-gas electron configuration.
They achieve the electron configuration of a noble gas.
In noble gas notation, you don't have to write the electron configuration up to that noble gas. You simply put the noble gas in brackets [noble gas] and then continue to write the electron configuration from that point. It just makes it shorter and easier to write electron configurations for elements with a lot of electrons.
Aluminum needs to lose 3 electrons to gain a noble gas electron configuration.