Which of the following is described by the equation H2O(l) + heat → H2O(g)?
Answer: +H30
The valence of lead is 4.
Hence the name of the compound is called Lead (IV) oxide.
<h3>Further explanation</h3>
Given
PbO₂ compound
Required
The valence of Pb
Solution
The oxidation number of element O in the compound = -2, except for OF₂ the oxidation state = + 2 and the peroxides (Na₂O₂, BaO₂) the oxidation state = -1 and superoxide, for example KO₂ = -1/2.
The oxidation state in the uncharged compound = 0,
So The oxidation state of Pb :
Pb + 2.(-2) = 0
Pb - 4 = 0
Pb = +4
Answer:
700,000 holes
Explanation:
When heat energy occurs to produce free electrons, the number of free electrons produced is directly proportional and equal to the number of holes it produces at that time.
Hence, if silicon crystal (pure) has 700,000 free electrons, then the number of holes it have is also 700,000.
<span>An independent variable is a variable that is not affected in the experiment. It is what experimenter controls. Here, the concentration of salt is the independent variable.
On the other side, a dependent variable is called dependent because it depends on the independent variables. It is what is affected and observed during the experiment. Here, the freezing point of water is affected and, thus, it is the dependent variable.
A controlled variable is a variable that must remain unchanged (must be constant) during the experiment so that the effect on the dependent variable depends only on the independent variable. Here, the volume of water must be constant, so it is the controlled variable.
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