Atomic Symbol
This is the chemical symbol of a chemical element.
Capitalised
Every element has a one or two (or three, if the element doesn't have an official name yet) letter symbol.
The name of the element symbolized by the letter A on the periodic table will depend on the specific element being referred to. There is no specific element that is universally represented by the letter A.
Letter X could be any element. It has charge depending on name of element.
it's an element
No chemical element begins with the letter Q.
Lithium has a letter 'H' as the fourth letter.
No chemical element begins with the letter W.
Nitrogen
its a letter
The silvery metallic element that ends with the letter "l" is "nickel."