Density offers a convenient means of obtaining the mass of a body from its volume or vice versa; the mass is equal to the volume multiplied by the density (M = Vd), while the volume is equal to the mass divided by the density (V = M/d).
M = V d 
M = 1.4 * 2 = 2.8 kg 
 
        
             
        
        
        
Matter either loses or absorbs energy when it changes from one state to another. For example, when matter changes from a liquid to a solid, it loses energy. The opposite happens when matter changes from a solid to a liquid. For a solid to change to a liquid, matter must absorb energy from its surroundings.
        
             
        
        
        
Explanation:
Dark Energy. Dark Energy is a hypothetical form of energy that exerts a negative, repulsive pressure, behaving like the opposite of gravity. It has been hypothesised to account for the observational properties of distant type Ia supernovae, which show the universe going through an accelerated period of expansion
 
        
             
        
        
        
Hey there!
In a gas state, particles have lots of energy, so they move around very rapidly, hitting each other and flowing around, that's why you see them moving so freely. Because they have so much energy, the substance is likely to be harder, as it can obtain more thermal energy, or heat.
Hope this helps!