Answer:
Water has 18 grams per mole so 9 grams is 0.5 moles of water. There are 6.022* 10^23 molecules in a mole. Each water molecule contains one oxygen and two hydrogens.
x = 20 long tables
y = 5 round table
Explanation:
We have the following system of equations:
x + y = 25
8x + 6y = 190
From the first equation we have:
x = 25 - y
And we replace x in the second equation:
8(25 - y) + 6y = 190
200 - 8y + 6y = 190
200 - 2y = 190
200 - 190 = 2y
10 = 2y
y = 5
Now we insert the value of y in the next equation:
x = 25 - y
x = 25 - 5
x = 20
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system of equations
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Answer: obey the "law of conservation of mass".
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Atoms are generally neutral because they have an equal amount of protons and electrons.