An element is a mixture of two isotopes. One isotope has an atomic mass of 34.969 amu and an abundance of 64.88%. The other isotope has an atomic mass 36.966 amu.
 
        
             
        
        
        
Answer:
(b) IE₂ of Ga >  IE₂ of Ge 
Explanation:
Electronic configuration of Ga is [Ar] 3d¹⁰4s²4p¹
Electronic configuration of Ge is [Ar] 3d¹⁰4s²4p²
After 1st ionisation , Ga  becomes [Ar] 3d¹⁰4s² and becomes stable . Its
 2 nd ionisation requires higher amount of ionisation energy. In case of Ge , there are 2 electrons in outermost orbital so it becomes stable after ionisation of 2 electrons. 
 
        
                    
             
        
        
        
Answer:
a: chemical change because the change cannot be reversed.
b: physical change because the action can be reversed.
c: chemical change.
d:chemical change.
any change that cannot be reversed is a chemical change and any change that can be reversed is a physical change.
 
        
             
        
        
        
<span>thermal energy
hope this helped</span>
        
             
        
        
        
Answer:
ITS FALSE electricity doesn't travel through wood same with cement!