In the periodic table, elements (other than noble gases) tend to achieve there duplet/octet electron configuration (having a completely filled outermost shell) by either donating or accepting electrons. Generally, metals donate electrons to become positively charged cations while non-metals accept electrons to become negatively charged anions.
Oxygen accepts two electrons in order to have a fully filled outermost shell and become O²⁻ or oxide ion. Oxygen itself is an element and it's ion is called oxide ion
Oxide ion. because oxsgen has 6 electrons in its orbit or subshell, so it needs only two to achieve the octet rule by gaining 2 electrons.
Gaining electrons means that the element become an anion ion
From the experiment it can be concluded that a material or object which has a density that is lesser than water floats. Also, the object that has a density greater than that of water will sink. This is because density is the measure of the amount of substance that is occupied by an object in a given volume.
