Question

9 multiple choice 2 points the graph shown represents the relationship between the heat energy added and the temperature of substance x. substance x has a mass of 1.00 kilogram and is being heated from 20°c to 750°c. in which phase is substance x when its temperature is 250°c? solid liquid gas plasma

Explanation:

When a substance is heated, during phase - change (melting or vaporization), the temperature remains constant. In the given graph, the first horizontal line (constant temperature) is the melting phase (solid - liquid phase change). After the melting phase (when the temperature starts to rise again), the substance is in the liquid phase until the vaporization (second horizontal line) starts. A temperature of \(250^{\circ}C\) is after the melting phase (where the temperature was constant around \(200^{\circ}C\)) and before the vaporization phase (which starts at around \(650^{\circ}C\)).

Answer:

liquid