Answer:
rip there isnt a photo
Explanation:
i do know a lot about cells tho lol
Density = mass/volume
Therefore,
Density = 60g/30cm
Answer: 
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for reaction of potassium superoxide with carbon dioxide to produce oxygen and potassium carbonate will be:

Answer: It means that the energy is being stored or preserved to be used at a later time.
Your question was a little vague, so if this isn't the answer you were looking for, just let me know and I'll fix it.
Hope this helps! Good luck! :D
The most common gas in the troposphere is nitrogen.
I hope this helps!