Write the symbol for each of the following ions:
(a) the ion with a 1+ charge, atomic number 55, and mass number 133
(b) the ion with 54 electrons, 53 protons, and 74 neutrons
(c) the ion with atomic number 15, mass number 31, and a 3 - charge
(d) the ion with 24 electrons, 30 neutrons, and a 3+ charge

Explanation:

Atomic number means total number of protons present in an element. Whereas mass number or atomic mass means the sum of total number of protons and neutrons in an atom or element.

When an atom is neutral then it contains same number of protons and electrons.

Symbol for any element showing atomic number and atomic mass is .

(a) the ion with a 1+ charge, atomic number 55, and mass number 133 will be Cesium and it is represented as .

(b) the ion with 54 electrons, 53 protons, and 74 neutrons will have mass number as (53 protons + 74 neutrons) = 127. Iodine is the element that has mass number 127. There will be a negative charge also as it contains 54 electrons.

Hence, symbol for this element will be .

(c) the ion with atomic number 15, mass number 31, and a 3 - charge will be phosphorous. Symbol for this element will be .        

(d) the ion with 24 electrons, 30 neutrons, and a 3+ charge in elemental state will have in total 27 electrons and 30 neutrons. So, its mass number will be (27 + 30) = 57. Symbol of this element will be  

the answer is 303.15 or 303