Answer:
Oxidation state shows the total number of electrons which have been removed from an element (a positive oxidation state) or added to an element (a negative oxidation state) to get to its present state
Explanation:
When a metal replaces another metal in solution, we say such a reaction has undergone a single displacement reaction.
In such a reaction, metal higher up in the activity series replaces another one due to their position.
To known the metal or metals that will replace the given copper, we need to reference the activity series of metals.
Every metal higher than copper in the series will displace copper from the solution.
So, there metals are: potassium, sodium, lithium, barium, strontium etc.
The answer is 2 electrons.
The electron configuration of calcium is 2:8:8:2
Calcium has two electrons in its outermost shell. These are its valence electrons and are the ones used in bonding with other elements. Valence electrons of an atom are those electrons that are in its outer energy shell or that are available for bonding.
Calcium is a metal. When metals react with non-metals, electrons are transferred from the metal atoms to the non-metal atoms forming ions. The resulting compound is known as an ionic compound.
For example, when calcium metal reacts with chlorine gas, calcium gives up its two valence electrons and Chlorine accepts them resulting in a new substance called calcium chloride in which the two elements have ended up forming ionic bonds.
