The sodium ion may be abbreviated as Na+ or as simply Na. Sodium can occur as a salt in a crystalline solid. Sodium chloride (NaCl), sodium phosphate (Na2HPO4) and sodium bicarbonate (NaHCO3) are commonly occurring salts. These salts can be dissolved in water or in juices of various foods.
A Reference Point is something you use to determine the position of an object, but the reference point has to be something that doesn't move at all. For Example: A Tree. A Reference Point is something you use to determine the position of an object, but the reference point has to be something that doesn't move at all. For Example: A Tree.
For other uses, see Reference (disambiguation). Reference is a relation between objects in which one object designates, or acts as a means by which to connect to or link to, another object. The first object in this relation is said to refer to the second object. The second object, the one to which the first object refers, is called the referent of the first object.