Sound waves. 
 Radio waves and Microwaves are non-ionizing radiation. Gamma waves are ionizing radiation
        
             
        
        
        
Answer: X is a Solid; Y is a Gas
Explanation:
There are three (3) states of matter. They are: Solid, Liquid and Gases. 
 Substance X and Y, belong to the states of matter. 
A Solid is a substance that retains its SIZE and SHAPE without need of a container (as opposed to a liquid or gas).
Thus, it will most likely be concluded that: substance X is a Solid; while Y is a Gas
 
        
             
        
        
        
Speed and velocity is a scalar and vector quantity of a similar parameter, respectively. They both refer to how fast an object moves. However, the speed only has to do with the magnitude. The velocity takes into account the sign which indicates the direction of the movement. For example, the value is -5 m/s. The speed is 5 m/s, but the velocity is 5 m/s moving downwards because the negative sign denotes downward movement or movement to the left.
        
             
        
        
        
It’s lower, hope this helps with your issue and helps solve your problem, no problem