Use the table to answer the questions below:

When the temperature in a room increases from [tex]$25^{\circ} C$[/tex] to [tex]33^{\circ} C$[/tex], which substance changes from a solid to a liquid?

\begin{tabular}{|c|c|c|}
\hline
Substance & Melting point [tex]^{\circ} C[/tex] & Boiling point [tex]^{\circ} C[/tex] \\
\hline
Gallium (Ga) & 30 & 2204 \\
\hline
Gold (Au) & 1064 & 2856 \\
\hline
Methane (CH₄) & -182 & -161 \\
\hline
Nitrogen (N₂) & -210 & -196 \\
\hline
\end{tabular}

In a lab, methane and nitrogen are cooled from [tex]-170^{\circ} C[/tex] to [tex]-200^{\circ} C[/tex]. The methane freezes, and the nitrogen [tex]\square[/tex].

When gold is heated to [tex]2856^{\circ} C[/tex], it changes from a liquid to a [tex]\square[/tex].



Answer :

To find the correct answers, we need to analyze the provided information using the given table and given conditions.

1. From the temperature change from [tex]$25^{\circ}C$[/tex] to [tex]$33^{\circ}C$[/tex], and the substance changing from a solid to a liquid:
- Let's look at the substances:
- Gallium (Ga) has a melting point of [tex]$30^{\circ}C$[/tex].
- Gold (Au) has a melting point of [tex]$1964^{\circ}C$[/tex].
- Methane (CH4) has a melting point of [tex]$-182^{\circ}C$[/tex].
- Nitrogen (N2) has a melting point of [tex]$-210^{\circ}C$[/tex].

- Only Gallium (Ga) fits the condition as its melting point, [tex]$30^{\circ}C$[/tex], is between [tex]$25^{\circ}C$[/tex] and [tex]$33^{\circ}C$[/tex], meaning it would change from a solid to a liquid in this temperature range.

Thus, the substance changing from a solid to a liquid between [tex]$25^{\circ}C$[/tex] and [tex]$33^{\circ}C$[/tex] is Gallium (Ga).

2. In the lab, when methane and nitrogen are cooled from [tex]$-170^{\circ}C$[/tex] to [tex]$-200^{\circ}C$[/tex]:
- Methane (CH4):
- Freezing point: [tex]$-182^{\circ}C$[/tex].
- Starting at [tex]$-170^{\circ}C$[/tex] and cooling to [tex]$-200^{\circ}C$[/tex]:
Methane will freeze because [tex]$-200^{\circ}C$[/tex] is lower than its freezing point of [tex]$-182^{\circ}C$[/tex].

- Nitrogen (N2):
- Boiling point: [tex]$-196^{\circ}C$[/tex].
- Freezing point: [tex]$-210^{\circ}C$[/tex].
- Starting at [tex]$-170^{\circ}C$[/tex] and cooling to [tex]$-200^{\circ}C$[/tex]:
Nitrogen behaves interestingly. Given that its boiling point is [tex]$-196^{\circ}C$[/tex] and freezing point is [tex]$-210^{\circ}C$[/tex], it will transition through liquid state and will freeze below its freezing point.

Thus, the methane freezes, and the nitrogen freezes as well.

3. When gold is heated to [tex]$2560^{\circ}C$[/tex]:
- Gold (Au):
- Melting point: [tex]$1964^{\circ}C$[/tex].
- Boiling point: [tex]$2567^{\circ}C$[/tex].

- Given that gold’s melting point is [tex]$1964^{\circ}C$[/tex], gold will already be in a liquid state when heated beyond this point. Since [tex]$2560^{\circ}C$[/tex] is below its boiling point of [tex]$2567^{\circ}C$[/tex], gold will still be in its liquid state at [tex]$2560^{\circ}C$[/tex] and not converted to gas yet.

Thus, gold when heated to [tex]$2560^{\circ}C$[/tex] changes from a solid to a liquid.

### Summary:
- The substance changing from solid to liquid when the temperature increases from [tex]$25^{\circ}C$[/tex] to [tex]$33^{\circ}C$[/tex] is Gallium (Ga).
- When methane and nitrogen are cooled from [tex]$-170^{\circ}C$[/tex] to [tex]$-200^{\circ}C$[/tex], methane freezes, and nitrogen freezes.
- When gold is heated to [tex]$2560^{\circ}C$[/tex], it changes from a liquid to a liquid (since it hasn't reached its boiling point).