Explanation:
A property which does not bring any change in chemical composition of a substance is known as physical property.
For example, blood is more viscous than water, its pH is slightly alkaline, its temperature is about  (
 ( )  .
)  .
On the other hand, a property which changes chemical composition of a substance is known as a chemical property.
For example, precipitation, reactivity, toxicity etc are chemical property.
Sometimes, the change in color of a substance can also occur due to a chemical change.
Thus, we can conclude that following are the physical characteristics of blood.
- it is more viscous than water. 
- its temperature is about  ( ( ). ).
- the pH is slightly alkaline. 
- it is about 8% of one’s total body weight. 
 
        
             
        
        
        
The refractory period makes the cell rest. In this period, the cell becomes able to depolarize again by collecting ions.
        
                    
             
        
        
        
Over here a lead weight moved from sea level to the top of a mountain high and a sample of chlorine gas compression the density increases for the substances. 
Good luck
Regards 
BLACKSHARK
        
             
        
        
        
Answer:
In 1913, Niels Bohr proposed a theory for the hydrogen atom, based on quantum theory that some physical quantities only take discrete values. Electrons move around a nucleus, but only in prescribed orbits, and if electrons jump to a lower-energy orbit, the difference is sent out as radiation.
 
        
             
        
        
        
Answer:
If two atoms get close enough together then the electrons of each atom will be attracted to both nuclii. If the atoms get two close then the nuclii will repell each other. Single sided arrows represent attraction.
Explanation: