Answer:
Tree sap flows over the leaf and preserves it.
Explanation:
Amber would preserve the image.
To begin this, you'll first note down the valencies of atoms you're sure about.
K is always 1+
And O is always 2-, except for in peroxide where it is 1-.
So now you must remember that a compound is always neutral. Your net charge has to be 0.
K2Cr2O7.
K2 (1+ x 2) = 2+
Cr (2x) = 2x
O7 (2- ×7) = 14-
+2 +2x + (-14) = 0
•Simple algebra.
2x -12 = 0
2x = 12
x = +6.
Each Cr atom has an oxidation number of +6.
<u>Answer:</u> The density of sugar is 
<u>Explanation:</u>
To calculate the density of a substance, we use the equation:
We are given:
Mass of sugar = 316 g
Volume of box = 
Putting values in above equation, we get:
Hence, the density of sugar is
Answer:
how can I solve this ?4Al+3O2 produce 2Al2O3 find a) oxygen atoms needed to react with 5.4 g of aluminium b) grams of oxygen needed to react with 0.6 mol of aluminium?
(A) n=m/M,
n(Al)=5.4/27=0.2 moles
n(O2)=n(Al)*3/4=0.2*3/4=0.15 moles
Number of oxygen atoms= n(O2)*Avogadro's number
=0.15*6.02*10^23=9.03*10^22 oxgyen atoms
(B)
n=m/M
n(Al)=0.6/27=0.02222 moles
n(O2)=n(Al)*3/4=0.016666 moles
m=n*M
m(O2)=0.0166666*32=0.53333 grams
