Answer:
Three.
Explanation:
When counting the number of significant figures in a decimal number, you start counting from the right of the decimal point.
0
.00203
Counting from left to right from the decimal point , there are 5 digits.
However, the zeroes before any natural number is not counted as a significant figure.
0.00
203
Thus, there are
3
significant figures ie. 203.
Note: any other numbers added to the right of
0.00203
is also counted as a significant number.
eg.
0.002031
has 4 significant figures.
eg.
0.002030
has 4 significant figures.
Molar mass of copper is 63.546
so malar mass of the laccase is
4* 63.546
-------------- = 651.754
0.39
The answer to this question would be: resistance
When a patient developing a resistance to a certain drug, the same amount of doses will not exert the same effect as before. The effect will be lower, thus the doctor will need to increase the dose to increase the effect
<u>Answer:</u> The molecules of oxygen gas that will be reduced to water are 42 molecules
<u>Explanation:</u>
We are given:
The substance having highest positive 
potential will always get reduced and will undergo reduction reaction. Here, oxygen will undergo reduction reaction will get reduced.
will undergo oxidation reaction and will get oxidized.
Substance getting oxidized always act as anode and the one getting reduced always act as cathode.
The half reactions follows:
<u>Oxidation half reaction:</u> 
( × 4)
<u>Reduction half reaction:</u> 
( × 6)
<u>Overall reaction:</u> 
We are given:
Molecules of = 28
By Stoichiometry of the reaction:
4 molecules of reacts with 6 molecules of oxygen gas
So, 28 molecules of will react with = 
molecules of oxygen gas
Hence, the molecules of oxygen gas that will be reduced to water are 42 molecules
