Answer:b. gravitational, kinetic, thermal
Explanation:
The above explains the mechanism of the core forming process on earth/planet.
 It is believed that this process might has contributed significantly to a planet's early stages heating. The time when these core-forming event happened is thought to have been mainly completed very early when Earth was young . The type of this event rather than it being seen as a single catastrophic event, it is likely to have been as a result of contractions on the earth severally.
The addition of partially differentiated material from another giant impact the rate of this spasm , and it increases each time the planet's mass is to increased.
This is a little on the history of planetary evolution.
 
        
             
        
        
        
c. x-rays 
My answer is that x-rays or gamma rays have the greatest (or highest) frequency waves.
 
        
             
        
        
        
Answer:

Explanation:
Hello,
In this case, since we can consider hydrogen gas as an ideal gas, we check the volume-pressure-temperature-mole relationship by using the ideal gas equation:

Whereas we are asked to compute the moles given the temperature in Kelvins, thr pressure in atm and volume in L as shown below:

Best regards.
 
        
             
        
        
        
The correct option is this: SODIUM IS VERY REACTIVE BECAUSE IT DOES NOT HAVE A FULL VALENCE SHELL.
For an atom to attain an octet form, it must have eight electrons in its outermost shell. Elements with eight electrons in their outermost shells are un-reactive. Sodium has only one electron in its outermost shell, this makes it to be very reactive because it is very willing to react with suitable elements in order to become stable.
        
                    
             
        
        
        
It would be 187 75 Re since 76 - 1 is 75 and number 2 would be beta particle and a positron.