C:H:O = 40/12 : 6,7/1 : 53,3/16 = 3,33 : 6,7 : 3,33 ≈ 1 : 2 : 1 
CH₂O
        
             
        
        
        
Answer:
1. Main sequence stars have different masses. The common characteristic they have is their source of energy. They burn fuel in their core through the process of fusing hydrogen atoms into helium.
2. Supergiants are among the most massive and most luminous stars. Supergiant stars occupy the top region of the Hertzsprung–Russell diagram with absolute visual magnitudes between about −3 and −8. The temperature range of supergiant stars spans from about 3,400 K to over 20,000 K.
3. Supergiants develop when massive main-sequence stars run out of hydrogen in their cores. 
4. a supernova occur When the pressure drops low enough in a massive star, gravity suddenly takes over and the star collapses in just seconds. This collapse produces the explosion. 
5. when a star has reached the end of its life and explodes in a brilliant burst of light
Explanation:
 
        
             
        
        
        
The law of definite proportions agrees with Dalton atomic theory.
What is Dalton atomic theory?
It state that all matters is made of very tiny particles called atom. atoms are individual particles which can not be created or be destroyed in a chemical reactions. Atoms of given elements are identical in mass and chemical properties. Atoms of
different elements have different masses and chemical properties.
The law of definite proportions also known as proust's law ,state that a chemical compound contain the same proportion of elements by mass.this law is one of the stoichiometry .
Thus ,
This is the reason why it is agrees with dalton atomic theory.
To know more about Dalton atomic theory click-
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Answer:
strength and vitality required for sustained physical or mental activity
Explanation: