This is late but for anyone else who needs it...It's D. Far left
Answer is: <span>the pH value(level) is the independent variable.</span><span>
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Missing question: <span>We conducted an experiment where we added 0.5 g of lactose to 5 different test tubes all containing 5 different pH levels. What is the independent variable?
In this experiment pH level changes, so results depend on different pH values.
Mass of lactose is same during experiment,so t</span>he number of molecules of product formed per minute is the <span>dependent variable.</span>
Answer:
Explanation:
Lewis dot structures represent the symbol of an atom we're looking at and the number of valence electrons it has. This number is represented by the sum of dots around the symbol.
- Potassium is in group 1A, this means it only has one valence electron, so we draw K with one dot in its Lewis diagram;
- Argon is in group 8A, this means it has eight valence electrons, so we draw Ar with 8 dots around it in its Lewis diagram;
- Silicon is in group 4A, this means it has four valence electrons, so we draw Si with 4 dots around it in its Lewis diagram;
- Arsenic is in group 5A, this means it has five valence electrons, so we draw As with 5 dots around it in its Lewis diagram.
Those are represented in the image attached below:
Answer: he expected to find no darkening of the film all because it hadn't been exposed to sunlight yet.