Which statement gives a reason why scientist think that the universe began with an explosion
1 answer:
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Answer:
A
Explanation:
Recall that Δ<em>H</em> is the sum of the heats of formation of the products minus the heat of formation of the reactants multiplied by their respective coefficients. That is:
Therefore, from the chemical equation, we have that:
Remember that the heat of formation of pure elements (e.g. H₂) are zero. Substitute in known values and solve for hydrazine:
In conclusion, our answer is A.
To get the number of gold atoms, you have to divide the mass of the gold by the mass of the gold atom. It follows this simple equation 
.
Let x be the number of gold atoms. Plug in the values to a calculator.
x =
Both have the same units so the unit gram(g) can be cancelled.
x then would be equal to 1.53x10^22. So there are 1.53x10^22 atoms of gold in 5 g of gold
Let x be the number of gold atoms. Plug in the values to a calculator.
x =
Both have the same units so the unit gram(g) can be cancelled.
x then would be equal to 1.53x10^22. So there are 1.53x10^22 atoms of gold in 5 g of gold