Answer:
a. PbO.
Explanation:
- The formula unit of a stable chemical compound should maintain that the overall charge of the compound is zero <em>(not charged)</em>.
- The formula unit of a compound is represented by the lowest ratio numbers of the ions forming the compound.
<em>Choice a:</em> is the right answer PbO
- That lead is divalent cation Pb²⁺ and O is considered as a divalent anion O²⁻.
- So, the formula unit contains Pb:O with a ratio of 1:1 (PbO)
<em>Choice b: </em>is a wrong choice Li₂B
- The lithium cation is a monovalent cation Li¹⁺ and boron is a trivalent cation B³⁺, so we can not do that.
<em>Choice c:</em> is a wrong choice Al₂Pb₃
- that Al is a trivalent cation Al³⁺ and Pb is a divalent cation Pb²⁺, so we can not do this for the two cations.
<em>Choice d:</em> is a wrong choice ClO
- that Cl may act as Cl¹⁺ and O acts as O²⁻, so the right formula unit should be Cl₂O.
O2 isn't necessary for rusting, but some source of oxygen is required. Rust is just another name for iron oxide, and without oxygen there can't be oxide.
Hope this helps,
Davinia.
Answer:
Which sentence from the passage shows that the function of the river depicted here has carried through to modern times?
Explanation: