Question

When an atom is represented by the symbol , the value of A is the a. number of neutrons in the atom. b. number of protons in the atom. c. atomic mass of the element. d. total number of electrons and neutrons in the atom. e. total number of protons and neutrons in the atom.

Answer 1

The answer to your question is c and e

Step-by-step explanation:

a. number of neutrons in the atom. This is incorrect the number of neutrons is just represented as # neutrons

b. number of protons in the atom. It's incorrect, the number of protons is represented as # protons or as atomic number (Z).

c. atomic mass of the element. This is correct, we use letter A to identify the atomic mass of an element.

d. total number of electrons and neutrons in the atom. This is wrong, in chemistry we never identify the number of electrons and neutrons together with a letter.

e. total number of protons and neutrons in the atom. This is correct, the number and protons and neutrons is the atomic mass of an element and is identified with the letter A.

Answer 2

Answer: e. total number of protons and neutrons in the atom.

Step-by-step explanation:

General representation of an element is given as:
`_Z^A\textrm{X}`

where,

Z represents Atomic number

A represents Mass number

X represents the symbol of an element

Mass number (A) is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons

Atomic number (Z) is defined as the number of protons or number of electrons that are present in an atom.

Atomic number = Number of electrons = Number of protons

Thus A represents total number of protons and neutrons in the atom.