Dmitri Mendeleev
<span> Dmitri Mendeleev and Lothar Meyer individually came up with their own periodic law "when the elements are arranged in order of increasing atomic mass,
certain sets of properties recur periodically.</span>
Answer ; The correct answer is : 346 m/s .
Sound is a type of longitudinal wave , which is produced when a matter compress or refracts .
Speed of sounds depends on factors like medium , density , temperature etc .
Effect of Temperature on speed of sounds :
When the temperature increases , molecules gains energy and they starts vibrating and with higher temperature vibration becomes fast . So the waves of sounds can travel faster due to faster vibrations . Hence , speed of sounds is directly proportional to the temperature or speed of sounds increases with increase in temperature .
The speed of sounds at 0⁰C is 331 
The relation between speed of sound and temperature is given as :

Given : Temperature = 25 ⁰ C
Plugging values in formula =>



Answer:
e. 8.04*10^4
Explanation:
80.4 g converted to mg is 80,400. 8.04*10^4= 80,400
Nearly all life on Earth gets its energy from the sun, and the sun gets its energy through the process of nuclear fusion, which is why these type of energy is important to life on Earth.