Question

consider a substance that is present in a sealed container in its solid state at a temperature well below its melting point. over the course of about 15 minutes, the container is heated. at first, the application of heat causes the temperature of the substance to increase until it reaches its melting point temperature. at its melting point temperature, heat is continually added, causing the solid to transition to a liquid at a constant temperature. once all the solid has melted, the substance is heated to its boiling point temperature. at its boiling point temperature, the addition of heat causes the liquid to transition to a gas at a constant temperature. once all the liquid has boiled, the sample continues to be heated (cautiously), causing the temperature of the gas to increase. this process is depicted in figure 1.
figure 1
title:
independent variable:
dependent variable:
figure 1 temperature (degrees celsius) time (sec) melting boiling

Explanation:

Step1: Determine the Title

The graph shows the temperature change of a substance over time as it undergoes phase changes (melting, boiling) when heated. So the title should relate to temperature vs time during heating and phase changes. Combining the context, "Temperature vs Time During Heating and Phase Changes of a Substance" (using the provided elements, we can also use the structure with the process: like "Heating Curve of a Substance (Including Melting and Boiling)"). But from the options, we can use the relevant terms. The graph is Figure 1, and the process involves melting and boiling while heating, so a suitable title is "Temperature vs Time for a Substance Undergoing Melting and Boiling (Figure 1)". But more precisely, the x - axis is time (sec), y - axis is temperature (°C), and the process includes melting, boiling, and heating. So the title can be constructed as "Temperature (°C) vs Time (sec) for a Substance During Heating, Melting, and Boiling (Figure 1)".

Step2: Identify Independent Variable

The independent variable is the one that is manipulated or is on the x - axis. In the graph, the x - axis is Time (sec), so the independent variable is Time (sec).

Step3: Identify Dependent Variable

The dependent variable is the one that depends on the independent variable and is on the y - axis. The y - axis is Temperature (°C), so the dependent variable is Temperature (degrees Celsius).

Answer:

Title: Temperature vs Time for a Substance During Heating, Melting, and Boiling (Figure 1) (or using the provided elements: can be "Heating Curve of a Substance (Including Melting and Boiling) - Figure 1")
Independent Variable: Time (sec)
Dependent Variable: Temperature (degrees Celsius)

(If we have to use the exact options given at the bottom:
Title: Figure 1: Temperature vs Time During Melting and Boiling of a Substance
Independent Variable: Time (sec)
Dependent Variable: temperature (degrees Celsius)
)