Answer:
An ion is an atom or group of atoms that has an electric charge. When an atom loses an electron, it loses a negative charge and becomes a positive ion. When an atom gains an electron, it gains a negative charge and becomes a negative ion. a sodium ion forms when a sodium atom loses one electron and becomes positively charged. a chloride ion forms when a chlorine atom gains one electron and becomes negatively charged.
Hope this helps,
       Arabella
 
        
             
        
        
        
The direction of the magnetic field would be going up.
        
             
        
        
        
Answer : Mass
Explanation : Mass measures the amount of matter in a substance or an object.
 
        
                    
             
        
        
        
Exothermic reaction is when the system releases energy to the surrounding, the energy (in the perspective of the system) will have a sign of negative, as the system is transferring energy towards the surrounding.
Endothermic reaction is when the system is absorbing energy from the surrounding, the energy (in the perspective of the system) will have a sign of positive, as energy is transferred to the system.