a) the kinetic energy decreases as in a gas, the particles are widespread and move freely but in a liquid, their movement is more limited
 
        
             
        
        
        
Answer:
<em>Varying frequency</em> between both waves accounts for difference in speed.
Explanation:
The speed of a wave is dependent on four major factors: 
- wavelength
- frequency
- medium, and 
- temperature 
Assuming equal temperature and medium of travel of these sound waves, and given that the wavelength (that is distance of travel) is equal, the only varying factor would be their frequency.
Wave speed is calculated by multiplying the wavelength times the frequency 
⇒ Speed = λ * <em>f</em>
 
        
                    
             
        
        
        
Answer:
Electric cars are much faster than their combustion counterparts.
Explanation:
This is because electric cars can produce high torque from the get go, whereas Combustion engines reach the torque after gaining speed
 
        
             
        
        
        
d. When aluminum-28 undergoes beta decay, silicon-28 is produced.
Explanation:
When the nuclei of aluminium-28 decays, it produces silicon- 28: 
     Aluminium    ²⁸₁₃Al
     Silicon 28      ²⁸₁₄Si
     beta particle     ⁰₋₁
        
            ²⁸₁₃Al        →          ²⁸₁₄Si      +        ⁰₋₁
This way, the mass and atomic number are conserved. 
Conservation of mass number: 
                 28 = 28 + 0,  28 = 28
                  13 = 14 -1 ,       13 = 13 
Learn more: 
Balancing nuclear equations brainly.com/question/10094982
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