See if you can complete the following table using only what is on this page. Hint. Two of the entries are for the same element. Element
Symbol
Nuclear
Symbol
Atomic Mass
Protons Neutrons
Electrons in
Number Number
Neutral Atom
57
82
138
57
ola
Fe
59
26

Answer and Explanation:

The empty spaces should be completed step-by-step as follows:

First line:

Element symbol: La (it is the corresponding element for the atomic number 57)

Mass number = Atomic number + Neutrons = 57 + 82 = 139

Nuclear symbol: ¹³⁹₅₇ La because the atomic number is 57 and mass number is 139.

Protons: 57 (is equal to the atomic number for a neutral atom)

Electrons in neutral atom = Atomic number = 57

Second line:

Element symbol: La (it is the corresponding element for the atomic number 57 and mass number 138)

Atomic number: 57 (from the Periodic Table, for La)

Mass number = 138 (from the nuclear symbol)

Protons: 57 (is equal to the atomic number for a neutral atom)

Neutrons = Mass number - Atomic number = 138 - 57 = 81

Electrons in neutral atom = Atomic number = 57

Third line:

Atomic number: 26 (from the Periodic Table, for the element Fe)

Protons: 26 (is equal to the atomic number for a neutral atom)

Neutrons = Mass number - Atomic number = 59 - 26 = 33

Nuclear symbol: ⁵⁹₂₆ Fe because the atomic number is 26 and mass number is 26.

the answer is 303.15 or 303

it means there are 3 atoms of oxygen