The atoms of elements can gain or lose electrons and become ions. Ions are charged particles that have gained or lost electrons. The atoms of elements can gain or lose electrons to form monatomic ions (made from a single atom of an element).
        
                    
             
        
        
        
Answer:
The answer is
<h2>3.68 g/mL</h2>
Explanation:
The density of a substance can be found by using the formula
<h3>

</h3>
From the question
mass of substance = 12.50 g
volume = 3.4 mL
The density of the substance is

We have the final answer as
<h3>3.68 g/mL</h3>
Hope this helps you
 
        
             
        
        
        
Answer:
Barium-138
Explanation:
The mass number is the atomic number + the number of neutrons. ... Identify the atom whose nucleus is composed of 56 protons and 82 neutrons. Barium-138 (the number of protons identifies the atom) Gallium has two naturally occurring isotopes: Ga-69 with a mass of 68.9256 amu and a natural abundance of 60.11% and Ga-71.