Answer:
consist of either a single capital letter or a capital letter and a small letter.
Step-by-step explanation:
A chemical reaction can be defined as a reaction in which two or more atoms of a chemical element react to form a chemical compound.
In Chemistry, a chemical element can be defined as any pure substance that is typically made up of only atoms and cannot be broken down into simpler substances through chemical processes. Thus, the atomic number (the number of protons in the nuclei of an atom) of a particular chemical element distinguishes from other chemical elements.
Generally, all chemical elements are denoted or represented by a symbol, which may either be single capital letter or a capital letter and a small letter.
This ultimately implies that, the symbols for elements with accepted names consist of either a single capital letter or a capital letter and a small letter. For example, the symbol for sodium is Na, copper is Cu, carbon is C, oxygen is O, iron is Fe, nitrogen is N, magnesium is Mg, potassium is K, argon is Ag, hydrogen is H, helium is He, phosphorus is P, etc.