Respuesta :
Answer:
55
Explanation:
mass number is neutron + proton
25+30
=55
note that the atomic number is =proton
The value of the mass number is 55.
The formula for mass number is as follows:-
[tex]Mass number = Number of protons+Number of neutrons[/tex]
Substitute 25 for number of protons and 30 for number of neutrons in the above equation as follows:-
[tex]Mass number=25+30\\=55[/tex]
Hence, the value of the mass number is 55.
To know more about:-
brainly.com/question/18964760