Answer:
- They are highly reactive metals
- They have low electro negativity
- They have low ionization energy 
- They don't exist alone in nature 
- They have low densities
Explanation:
Alkali metals are the elements in group 1 of the periodic table. They include Sodium, Lithium, Potassium e.t.c.
Due to the fact they have one atom in their outermost shell, they are very unstable because they easily react with other elements and are therefore don't exist alone in nature but combined with other elements for this same reason. 
Since alkali metals don't easily attract other elements due to it's lone pair in the outer most shell, it can be said to have low electro negativity.
Also, they don't need energy to discharge their electrons since they are highly reactive due to their lone pair in the outermost shell and so we say they have low ionization energy.
Due to this reason, they also have low densities. 
 
        
             
        
        
        
Answer:
Approximately 
. 
Explanation:
Look up the specific heat of gaseous neon: 
.
Calculate the required temperature change:
.
Let 
 denote the mass of a sample of specific heat 
. Energy required to raise the temperature of this sample by 
:
.
For the neon gas in this question:
Calculate the energy associated with this temperature change:
.
 
        
             
        
        
        
A bowling ball. 
definition of dense-closely compacted in substance