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In a phase diagram, which of the following is the term used for a substance held at a temperature and pressure where the solid, liquid, and gaseous states of a substance exist simultaneously?    

A. Triple point

B. Critical temperature

C. Critical point

D. Absolute zero

Answer Explanation:

Triple point.

In a phase diagram, the term used for a substance held at a temperature and pressure where the solid, liquid, and gaseous states of a substance exist simultaneously is the triple point.

The triple point is a unique point on a phase diagram where the three states of matter (solid, liquid, and gas) can coexist in equilibrium.

At the triple point, the temperature and pressure of the substance are fixed.

Option B, critical temperature, is the temperature at which a gas cannot be liquefied, regardless of the pressure applied.

It is a characteristic property of a substance and is typically higher than the boiling point of the liquid at standard pressure.

Option C, critical point, is the point on a phase diagram where the liquid and gas phases of a substance become indistinguishable.

At the critical point, the distinction between the liquid and gas phases disappears, and the substance becomes a supercritical fluid.

Option D, absolute zero, is the theoretical temperature at which all matter has zero thermal energy.

At absolute zero, all substances are in their solid state, but it is not relevant to a phase diagram, as it is a temperature where no transitions between states occur.

In summary, the term used for a substance held at a temperature and pressure where the solid, liquid, and gaseous states of a substance exist simultaneously in a phase diagram is the triple point, whereas the other options provided are not relevant or are characteristic properties of substances in different contexts.

Therefore, the Correct Answer is A.

More Questions on TEAS 7 Science

  • Q #1: Which of the following is the function of a totipotent cell?  

    A. Fights infectious diseases.

    B. Aids in the maturation of sex cells.

    C. Carries electrical impulses.

    D. Develops into any kind of cell.

    Answer Explanation

    A totipotent cell can self-renew by dividing and develop into the three primary germ cell layers of the early embryo and into extra-embryonic tissues such as the placenta.

    A fertilized egg is a totipotent stem cell and as such can develop into any specialized cell found in the organism.

    Choice A is not correct because totipotent cells do not fight infectious diseases.

    Choice B is not correct because totipotent cells do not aid in the maturation of sex cells.

    Choice C is not correct because totipotent cells do not carry electrical impulses.

     

  • Q #2: The measurement indicated by the line across the center of the cell is best referred to as which of the following?

    A. Area.

    B. Diameter.

    C. Volume.

    D. Radius.

    Answer Explanation

    Diameter.

    The diameter is the measurement of a straight line passing through the center of a circle and connecting two points on its circumference.

    In this case, the line across the center of the cell represents the diameter of the cell.

     

    Choice A, Area, is not the correct answer because area refers to the amount of space inside a two-dimensional shape.

    Choice C, Volume, is not the correct answer because volume refers to the amount of space occupied by a three-dimensional object.

    Choice D, Radius, is not the correct answer because radius refers to the distance from the center of a circle to its circumference and is half the length of the diameter.

  • Q #3: Which of the following is correct regarding the pH scale?

    A. A substance with a pH of 3 is two times more alkaline than a substance with a pH of 4

    B. A substance with a pH of 3 is two times more acidic than a substance with a pH of 4

    C. A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4

    D. A substance with a pH of 3 is 10 times more alkaline than a substance with a pH of 4

    Answer Explanation

    The pH scale is a logarithmic scale that measures the acidity or alkalinity of a solution.

    A solution with a pH of 7 is neutral, while a solution with a pH less than 7 is acidic and a solution with a pH greater than 7 is alkaline.

    Because the pH scale is logarithmic, each whole number change in pH represents a tenfold change in acidity or alkalinity.

    Therefore, a substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4.

    Choice A.

    A substance with a pH of 3 is two times more alkaline than a substance with a pH of 4 is not correct because it incorrectly states that the substance with a lower pH is more alkaline and also incorrectly states the magnitude of the difference in acidity or alkalinity.

    Choice B.

    A substance with a pH of 3 is two times more acidic than a substance with a pH of 4 is not correct because it correctly states that the substance with a lower pH is more acidic but incorrectly states the magnitude of the difference in acidity.

    Choice D.

    A substance with a pH of 3 is 10 times more alkaline than a substance with a pH of 4 is not correct because it incorrectly states that the substance with a lower pH is more alkaline.