Question

a temperature vs. time graph (heating curve) with y - axis labeled temperature (°c) and x - axis labeled time (min). there are blue boxes for labeling, and a draggables panel with options: solid, liquid, gas, melting, freezing, boiling, condensation.

Answer:

To solve this problem, we analyze the heating curve (temperature vs. time) and match each segment/flat line to the correct state or phase change:

1. Lowest Flat Line (First Box):

• At the start, the substance is absorbing heat but temperature is constant. This is melting (solid → liquid phase change, latent heat of fusion). Wait, no—wait, the lowest part: if temperature is constant and it’s the first flat line, actually, no—wait, the first flat line (closest to time=0) is when the substance is changing from solid to liquid? Wait, no, let's re-express:

Wait, the heating curve for a substance (like water) has:

• Solid (lowest temperature, before melting).
• Melting (flat line: solid → liquid, temperature constant).
• Liquid (temperature rises after melting).
• Boiling (flat line: liquid → gas, temperature constant).
• Gas (temperature rises after boiling).

Let’s map each box (from bottom to top):

1. Bottommost Box (Crossing the first rising line? No, the first box is on the lowest horizontal segment):

• This horizontal segment is when the substance is melting (solid → liquid), but wait, no—wait, the first horizontal line (lowest) is melting? No, actually, the first horizontal line (when temperature is constant) is the melting point: solid is turning into liquid. But the “Draggables” include “Solid”, “Liquid”, “Gas”, “Melting”, “Freezing”, “Boiling”, “Condensation”.

Wait, let's list the segments:

• First (lowest) horizontal segment: Temperature constant → phase change. Since we’re heating (time increases, temperature will rise later), this is melting (solid → liquid). But the box here is a “cross” (not a horizontal segment). Wait, the boxes:

Looking at the graph:

• The bottommost box (smallest) is on the initial rising line? No, the first box is a small rectangle on the lowest part (before the first horizontal line). Wait, maybe the segments are:

1. Bottommost box (crossing the first rising line? No, the first box is a small rectangle on the leftmost, below the first horizontal line):

• This is the Solid state (before melting: temperature rising while in solid phase).

1. Next box (horizontal segment):

• Temperature constant → Melting (solid → liquid phase change).

1. Next box (rising line after melting):

• This is the Liquid state (temperature rising while in liquid phase).

1. Next box (horizontal segment):

• Temperature constant → Boiling (liquid → gas phase change).

1. Topmost box (rising line after boiling):

• This is the Gas state (temperature rising while in gas phase).

Let’s confirm:

• Solid: Before melting, temperature increases (rising line) → the bottommost box (leftmost) is Solid.
• Melting: Horizontal line (temperature constant, solid → liquid) → next box (horizontal) is Melting.
• Liquid: After melting, temperature increases (rising line) → next box (rising) is Liquid.
• Boiling: Horizontal line (temperature constant, liquid → gas) → next horizontal box is Boiling.
• Gas: After boiling, temperature increases (rising line) → topmost box (rising) is Gas.

So the correct matches (from bottom to top) are:

1. Bottommost box: Solid
2. Next (horizontal) box: Melting
3. Next (rising) box: Liquid
4. Next (horizontal) box: Boiling
5. Topmost box: Gas

(Note: If the graph is a typical heating curve, this is the standard interpretation: solid → melting (solid→liquid) → liquid → boiling (liquid→gas) → gas, with temperature constant during phase changes (melting, boiling) and rising during solid, liquid, gas phases.)