Answer:
I have the same thing it's hard
Answer:
80.2
Explanation:
we subtract 18.2 from the total percentage which is 100%
The correct answer is:
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" F and Br , because they are in the same group" .
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Note:
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Choice [B]: "F and Br ; because they are in the same period" ; is incorrect; since "F" and "Br" are not in the same "period" (that is, "row").
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Choice [C]: "Na and Mg; because they are in the same group {"column"} ; is incorrect; since: "Na" and "Mg are NOT in the same group {"column"].
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Choice [D]: "Na and Mg" ; because they are in the same period {"row"}; is incorrect. Note: "Na" and "Mg" are, in fact, in the same period {"row"}. However, as aforementioned, {Mg and Na} are not in the same group {"column".}.
Note: The similiarities in physical and chemistry properties among elements are determined and organized — or tend to be so—by "groups" {"columns"} — NOT by "periods" {rows}.
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Answer:
Explanation:
Sn(WC)2
if it is tungsten carbide this should be correct but there are many versions of carbide
Sn(MC2)2
could also be possible
the 2 next to MC should be a subscript
Answer:
mass of CO2 = 88 g
Explanation:
It is stated in question that 18.7 g of oxygen remained unreacted which means that carbon is limiting reactant. Thus the amount of carbon dioxide produced depend upon the amount of carbon.
Given data:
mass of carbon = 24 g
total mass of oxygen 82.7 g
mass of unreacted oxygen = 18.7 g
mass of carbon dioxide = ?
Solution:
First of we will calculate the moles of carbon.
number of moles of carbon = mass of carbon / atomic weight
number of moles of carbon = 24 g/ 12 g/mol = 2 mol
Chemical equation:
C + O2 → CO2
now we compare the number of moles of carbon and carbon dioxide,
C : CO2
1 : 1
2 : 2
Now we will calculate the mass of carbon dioxide from moles.
number of moles of CO2 = mass of CO2 / molar mass of CO2
2 mol × 44 g/mol = mass
mass of CO2 = 88 g
