It is a chemical change
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D. to preserve the union. He changed the meaning of the war when he passed the Emancipation Proclamation in 1863.
Hope this helps. Please let me know if I'm wrong :)
You would convert the cg to g. 1.66 cg is 0.0166 g. then you add. 0.398 + 0.0166 = 0.4146. the answer is 0.4146 grams.
Answer:
The answer is 2.258 x 10^24 molecules are presented in 7.5 grams of H2.
Explanation:
I am going to use the chart that I attached to answer this question.
To convert grams to molecules we need to divide by the molar mass and multiply by 6.02 x 10^23, which is the value of a mole.
In this case the molar mass is 2 because the molar mass of H is 1 and we need to multiply by 2 to get the molar mass of 2 hydrogens.
Molar Mass = 1 x 2 = 2
Then, we need to divide the grams that we have by 2 to covert grams into moles. Finally, to convert moles into molecules we need to multiply the moles by 6.02 x 10^23.
7.5 grams / 2 = 3.75 moles
(3.75 moles)(6.02 x 10^23) = 2.258 x 10^24 molecules
Molecules are equal to atoms, so 2.258 x 10^24 molecules = 2.258 x 10^24 atoms