Calcium must lose 2 electrons and will become Ca2+. It will then have the electron configuration of Argon, a noble gas.
two electrons lost
Ca needs to lose 2 electrons to become Ca+2
It gains two to look like Ar.
The elements in group one and two react so easily because they have only one or two valence electrons, and the non metals, want those electrons. These group elements loose 1 or 2 electron to be stable instead of gaining 6 or 7 to complete the outer shell attain stable electronic configuration of a noble gas.
Only one electron lost.
two electrons lost
Selenium should gain two electrons and lose six electrons to achieve a noble gas electron configuration.
It must gain one electron to achieve a noble gas electronic structure, just like other halogens.
Ca needs to lose 2 electrons to become Ca+2
It gains two to look like Ar.
Lithium (Li) should lose 1 electron to get the configuration of the nearest noble gas (He).
Probably you want the electron cofiguration of uranium: [Rn]5f36d17s2 The ion U4+ lost four electrons.
calcium is normally [Ar] 4s2 if it is a 2+ ion, then it has lost 2 electrons so the configuration is just [Ar]
Gallium's atomic number is 31 and has a positive 3 charge which means it has lost 3 electrons to form an ion Ga3+. it has 28 electrons Hope this helps
It should loose 2 electrons to become a noble gas.
Elements that have gained or lost an electrons are called IONS. Ones that gained electrons (non-metals) and are therefore negatively charged, and known as ANIONS, and those that lost electrons (metals), are positively charged and known as CATIONS
They have one valence electron. If this electron is lost, the atoms form cations with the electronic configuration of the nearest noble gas.