It can't. Krypton is a noble gas, which means that all of its valence shells are filled with electrons. It doesn't want to be overfilled, nor does it want to be missing any. Though there are laboratory experiments making some types of ions, but it is very difficult and quick. You won't be seeing any ions of krypton made naturally.
Sulfur can both gain and lose electrons when forming ions. It can gain two electrons to form a sulfide ion (S2-) or lose two electrons to form a sulfide ion (S2+).
Bromine (Br) has 35 electrons, while Krypton (Kr) has 36 electrons. To have the same electron configuration as Krypton, Bromine would need to lose one electron.
Potassium will lose 1 electron to form a 1+ ion.
Beryllium will lose 2 electrons when forming an ion because it has 4 valence electrons and tends to reach a stable electron configuration by losing electrons to achieve a full outer shell.
Selenium can gain 1 electron or loss 2, 4, 6 electrons.
Krypton can gain a maximum of 2 electrons to achieve a stable octet configuration, forming the Kryptonide anion. It does not typically lose electrons.
Krypton tends to neither lose nor gain electrons since it has a full outer electron shell, making it stable.
Some atoms lose electrons, some gain electrons, and some share electrons depending on what elements are involved and what compound is forming.
Sulfur can both gain and lose electrons when forming ions. It can gain two electrons to form a sulfide ion (S2-) or lose two electrons to form a sulfide ion (S2+).
Strontium, a group 2 element, will lose 2 electrons to attain a noble gas configuration because it will achieve a stable electron configuration similar to the nearest noble gas, which is krypton. Strontium has 38 electrons in its neutral state, while krypton has 36 electrons. By losing 2 electrons, Strontium becomes Sr2+, and its electron configuration is similar to krypton.
Selenium may lose 2, 4 or 6 electrons and may gain 2 electrons.
Bromine (Br) has 35 electrons, while Krypton (Kr) has 36 electrons. To have the same electron configuration as Krypton, Bromine would need to lose one electron.
Beryllium would tend to lose its two electrons when forming a bond because it is easier to lose its two valence electrons rather than gain an additional five in order to obtain a full outer shell.
It will lose 2 to form Sr2+
Potassium will lose 1 electron to form a 1+ ion.
Oxygen will gain two electrons to achieve a full outer shell.
Beryllium will lose 2 electrons when forming an ion because it has 4 valence electrons and tends to reach a stable electron configuration by losing electrons to achieve a full outer shell.