The volume of the rock is 7mL. The correct option is c)7ml
From the question,
We are to determine the volume of the rock.
When an object is submerged in a container containing a liquid, the submerged object displaces a volume of liquid equal to the volume of the object.
That is,
Volume of object = Final volume - Initial volume
From the given information,
Initial volume = 40mL
Final volume = 47mL
∴ Volume of the rock = 47mL - 40mL
Volume of the rock = 7mL
Hence, the volume of the rock is 7mL. The correct option is c)7ml
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Coal and natural gas came from swamp environments, while oil came from open oceans.
B.
Coal came from swampy environments, while oil and natural gas came from open ocean environments.
C.
Coal, oil, and natural gas came from swamp environments.
D.
Natural gas and oil came from swamp environments, while coal came from open oceans.
Which is true about fossil fuels? The statement that is true about fossil fuels is Coal came from swampy environments, while oil and natural gas came from open ocean environments. The answer is letter B. The rest of the choices is not true for fossil fuel
b. a phosphate group.
c. a sugar group.
d. pyrimidines.
Fe³⁺ +e⁻ -> Fe²⁺ is the half reaction equation represents the reduction of an iron(II) ion
When an element or a compound gain electron , decreasing its oxidation number is called reduced and the half cell reaction is called Reduction reaction.
Fe³⁺ +e⁻ -> Fe²⁺ , Option C
In this reaction the Iron is gaining electron and the charge is getting reduced from +3 to +2 .
Therefore this half reaction equation represents the reduction of an iron(II) ion.
To know more about Reduction Reaction
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B. If I add substance X, then it will lower the temperature at which water freezes.
C. People should eat vegetables.
D. Bananas are better for you than chocolate. 2: Kobe is testing whether 100 g of substance A, 100 g of substance B, or 100 g of substance C produces more oxygen in a chemical reaction at 25°C. What is the independent variable?
A. the masses of the substances
B. the temperature of the substances
C. the amount of oxygen produced
D. the nature of the substances 3: A chemist measures the amount of mercury in sediment samples from three areas of a river (the source, the midway point, and the mouth). Which of the following is the most reasonable hypothesis for the chemist's experiment?
A. If a chemical plant near the source of the river is dumping mercury, then the mercury levels should be highest at the source and lowest at the mouth.
B. If a chemical plant near the source of the river is dumping mercury, then the mercury levels should be highest at the mouth and lowest at the midway point.
C. If a chemical plant near the source of the river is dumping mercury, then the mercury levels should be highest at the mouth and lowest at the source.
D. If a chemical plant near the source of the river is dumping mercury, then the mercury levels should be the same all along the river.
The correct options are as follows:
1. B.
In scientific investigation, an hypothesis refers to a supposition that is put forward to explain an observed phenomenon. A hypothesis is described as valid if it fulfilled five different conditions. The conditions are as follows:
1. It must be capable of empirical verification.
2. It must be express clearly and it must be definite and certain.
3. It must be specific and it is predictions must be clearly expressed.
4. It must be formulated in such a way that its content can easily be translated to understand the observed phenomenon that give birth to the hypothesis.
5. It should possess theoretical relevance.
2. D.
Scientific investigations usually make use of two major variables, these are dependent variables an independent variables. The dependent variable refers to the variable whose value depend on that of another variable. The independent variable on the other hand refers to that variable whose variation does not depend on the value of another variable. In the question given above, the natures of the three substances is the independent variable because their variation is not determined by any variable.
3. B.
If a chemical plant near the source of a water body is dumping mercury inside the water, then the highest amount of mercury will be found at the mouth of the river while the lowest quantity of mercury will be found at the middle of the water. This is because as the water waves are carrying the mercury deposits away from the mouth of the river, they will disperse it evenly in the river and thus its concentration will reduce compare to that present at the mouth of the river. The highest amount of mercury is found at the mouth of the river because that is where the mercury enters the water.