What type of ion forms when an atom loses electrons?

an electrically charged atom or group of atoms formed by the loss or gain of one or more electrons, as a cation (positive ion) which is created by electron loss and is attracted to the cathode in electrolysis, or as an anion (negative ion) which is created by an electron gain and is attracted to the anode. read more

A cation is formed when an atom loses electrons. An atom that loses electrons loses negative charge; therefore, it becomes positively charged. These atoms have a low affinity or attraction for electrons and are called electropositive atoms. read more

For example, an aluminum atom lose three electrons when forming its cation. A neutral aluminum atom has 13 protons and 13 electrons. When the aluminum atom loses 3 electrons, the resulting aluminum ion has 10 electrons and 13 protons. Since there are now 3 more protons than electrons, it develops an ion with a 3+ charge. read more