Answer:
it's a physical change
Explanation:
there there was no burning it was grabbing and just cutting
 
        
             
        
        
        
Answer:
A)  positive; added
Explanation:
Based on the reaction:
2NaHCO3(s) + 129kJ → Na2CO3(s) + H2(g) + CO2(g)
<em>2 moles of NaHCO3 requires 129kJ to produce 1 mole of Na2CO3, 1 mole of H2 and 1 mole of CO2.</em>
<em />
That means, the energy must be added being, thus, an exothermic reaction. The exothermic reactions have ΔH >0.
Thus, right answer is:
A)  positive; added
 
        
             
        
        
        
1. Francium
2. Nitrogen
3.rubidium
4. Krypton
        
             
        
        
        
Chemical equilibrium is reach when the concentrations of the product and reactants will no longer change with time. this does not mean that there is no change in concentration, only the net change is zero. the forward rate of reaction is now equal to backward rate of reaction.
        
             
        
        
        
In order to satisfy charge conservation and lepton number conservation the other products must be neutron.
<h3>
What is conservation of mass?</h3>
The principle of conservation of mass states that, the sum of the initial mass of reactants must be equal to final mass of the products.

The balanced reaction of radioactive decay of phosphorous shows conservation of mass.
Thus, in order to satisfy charge conservation and lepton number conservation the other products must be neutron.
Learn more about radioactive decay here: brainly.com/question/1383030
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