Answer:
x = 5 and y =4
Explanation:
An alkane is a hydrocarbon of general molecular formula CnH2n+2. The general formula for balancing the combustion equation of any alkane is;
CnH2n+2 + 3n+1/2O2 ------> nCO2 + (n+1) H2O
Where n is the number of carbon atoms in the alkane.
In C3H8 , n=3 so;
C3H2(3)+2 + 3(3)+1/2O2 ------> 3CO2 + (3+1) H2O
Then;
C3H8 + 5O2 ------> 3CO2 + 4H2O
Therefore;
x = 5 and y =4
First find the moles
moles of the calcium= 72.8 / 40
moles of calcium in 72.8g = 1.82mol
number of atoms= moles x Avogadro constant
atoms = 1.82 x 6.02x10+23
so the number of atoms is 1.096x10+24
<span>A. Exact ecological footprints are often difficult to calculate, but estimates can be useful in comparing populations.
</span>Which of the following could be said about ecological footprints? <u /> <u>Exact ecological footprints are often difficult to calculate, but estimates can be useful in comparing populations.</u><u />
NOT:
b. Ecological footprints can't be used to determine carrying capacity.
C. Ecological footprints don't take into account resources needed to absorb and manage wastes.
<span>D. The average ecological footprints for various countries are nearly identical.</span>
Answer:
Chlorine
Explanation:
Each arrow represents one electron. Most of the boxes are filled, meaning they have two electrons. The last box only has one arrow, so it only has one electron. If you add it up, you get 17, which is Chlorine.
The correct answer is letter D: Quartz.