Answer:
+4
Explanation:
In PbO2, oxygen exhibits an oxidation number of -2 (since it's not a peroxide or superoxide):
Let the oxidation number of Pb be x. Then, for the compound to be neutral, the oxidation numbers of all atoms should add up to zero.
⇒ x + (−2) + (−2) = 0
x = +4
So the oxidation no. of Pb is +4.
I hope this helps.
I believe this process is called cellular respiration.
Gas molecules have more freedom in motion—and gases can be thought of as more “disordered”—than molecules of a solid, which are rigidly held in place. When it comes to phases, the entropy increases as you go from a solid to liquid to gas (the gaseous state having the greatest entropy and the solid state having the least).
So, as a sample of solid iodine sublimes to form gaseous iodine, the entropy of the sample increases.
To dissolve in water, aluminum (Al) should form a compound with sulfate. Aluminum sulfate is the water soluble compound of aluminum. It has a chemical formula of Al2(SO4)3. It is used in industries as flocculating agent especially in the purification steps of drinking water and wastewater treatment plants.
Answer : The number of lone pairs of electrons around the central iodine atom are, 6 electrons
Explanation :
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
The representation of valence electrons of an atom by dots around the symbol of an element is said to be the Lewis-dot symbol.
In the representation of Lewis-symbol, one electron dot must put on each side of the element symbol then paired the electrons.
The given molecule is, 
As we know that iodine ans chlorine has '7' valence electrons.
Therefore, the total number of valence electrons in = 7 + 2(7) + 1 = 22
According to Lewis-dot structure, there are 4 number of bonding electrons and 18 number of non-bonding electrons.
Hence, the number of lone pairs of electrons around the central iodine atom are, 6 electrons
