Answer:
25
Explanation:
explain no need it is perfect
The statement the chemical makeup of the universe has changed dramatically provides evidence that supports the Big Bang Theory (Option D).
<h3>What is the Big Bang Theory?</h3>
The Big Bang Theory is a widely accepted theory in physics that states all the universe began with a huge explosion and form then matters expanded in space at the same time that it is cooling.
Therefore, with this data, we can see that the Big Bang Theory states that the chemical composition of the universe associated with hydrogen and helium modified since this explosion.
Learn more about the Big Bang Theory here:
brainly.com/question/1973038
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Answer:
Option A.
2Na + 2H2O —> 2NaOH + H2
Explanation:
To know which option is correct, we shall do a head count of the number of atoms present on both side to see which of them is balanced. This is illustrated below below:
For Option A:
2Na + 2H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
4 H >>>>>>>>>>>> 4 H
2 O >>>>>>>>>>>> 2 O
Thus, the above equation is balanced.
For Option B:
2Na + 2H2O —> NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 3 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
For Option C:
2Na + H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
2 H >>>>>>>>>>>> 4 H
1 O >>>>>>>>>>>> 2 O
Thus, the above equation is not balanced.
For Option D:
Na + 2H2O —> NaOH + 2H2
Reactant >>>>>>> Product
1 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 5 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
From the illustrations made above, only option A is balanced.
Answer: Mass of 
produced in this reaction was 6.56 grams
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.
Mass or reactants = Mass of 
+ mass of 
= 16.00 + 64.80 = 80.80 g
Mass of products = mass of aqueous solution + mass of + = 74.24 + x g
Mass or reactants = Mass of products
80.80 g = 74.24 + x g
x = 6.56 g
Thus mass of produced in this reaction was 6.56 grams
