Answer: A
Happens when familiar things are selectively ignored.
Answer:
D. Al(s) + O₂(g) → Al₂O₃(s)
Explanation:
Aluminum is a solid metal, so it is written as Al(s).
Oxygen is a diatomic gas, so we write this compound as O₂(g).
Aluminum oxide has the formula Al₂O₃ because in oxides the oxidation number of oxygen atom is -2 and for aluminum, the oxidation number is 3. Thus, we write this compound as Al₂O₃(s).
Now, we have to found the chemical equation in which the reactants (left side) are Al(s) and O₂(g) while the product (right side) is Al₂O₃(s). From the options, we can see that the correct is (D):
Al(s) + O₂(g) → Al₂O₃(s)
<span>Lead is most commonly used for protecting people from radioactive substances. </span>
Answer:
C. Nitrogen
Explanation:
All of the other options are mixtures making them substances, but nitrogen is an element. (while gold is an element, there are often times that gold is mixed with other elements, creating a substance)