Answer:
Nucleus
Explanation:
The nucleus serves as the cells command center, sending direction to the cell to grow, mature, divide, or die
 
        
             
        
        
        
Answer:
Explanation:
sp² hybridization is found in those compounds having double bond . 
Out of the given compounds only C₂H₂Cl₂ has double bond so this compound contains carbon with sp² hybridization . 
Rest have sp³ hybridization because they are saturated compounds .
 
        
             
        
        
        
 The answer is N2 + 3H2 yields 2NH3. The oxidation-reduction reaction means that there is electrons transfer during the reaction which means that the valence changed.
        
                    
             
        
        
        
Answer:
 A. releases a large amount of heat 
Explanation:
A reaction is said to be spontaneous if it can proceed on its own without the addition of external energy. A spontaneous reaction is not determined by the length of time, because some spontaneous reactions are completed after a long period of time. They are exothermic in nature. An example is the conversion of graphite to carbon which takes a long period of time to complete. Spontaneous reactions are known to increase entropy in a system. Entropy is the rate of disorder in a system.
In the combustion of fire, energy is released to the surroundings as there is a decrease in energy. This is an example of a spontaneous reaction because it is an exothermic reaction, which causes an increase in entropy and a decrease in energy.