The Step that is Usually done right before the experimentation in the Scientific Method is Developing a Hypothesis and asking a Question.
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~Izzy
B. Sand.
Sand would definitely increase friction because of the roughness of it surface. When its surface comes with another rough surface it would tend to increase friction. All other options given tend to reduce friction one way or the other.
Explanation:
The sum of all oxidation numbers in a neutral compound is zero. The sum of all oxidation numbers in a polyatomic (many-atom) ion is equal to the charge on the ion. The oxidation number of oxygen in a compound is usually –2. The oxidation state of hydrogen in a compound is usually +1.
The oxidation state of Al in Al(OH)
4
−
x+4(+1−2)=−1
∴x=+3
The oxidation state of Mn in MnO
2
y+2(−2)=0
∴y=+4
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