A student investigated some properties of lead and recorded the findings in the table below.

\begin{tabular}{|l|l|}
\hline \multicolumn{1}{|c|}{ Property } & \multicolumn{1}{|c|}{ Observation } \\
\hline color & dull gray \\
\hline density & [tex]$11.3 \, \text{g/cm}^3$[/tex] \\
\hline volume of sample & [tex]$3.00 \, \text{cm}^3$[/tex] \\
\hline melting point & [tex]$327^{\circ} \text{C}$[/tex] \\
\hline reaction with air & lead oxide forms on the surface \\
\hline electrical conductivity & conducts some electricity \\
\hline
\end{tabular}

Which statement is true with respect to the investigation?

A. The student investigated only the physical properties of lead.
B. The student investigated only the chemical properties of lead.
C. The student investigated more physical properties than chemical properties of lead.
D. The student investigated more chemical properties than physical properties of lead.



Answer :

To answer this question, it is essential to categorize each property into either physical properties or chemical properties.

Physical properties are characteristics of a substance that can be observed or measured without changing the substance's chemical identity. Chemical properties describe a substance's potential to undergo chemical change or reaction based on its composition.

Let's categorize the given properties:

1. Color - This is a physical property because it describes the appearance of the lead without altering its chemical structure.
2. Density - This is a physical property, as it describes how much mass is in a given volume and is measurable without changing the substance.
3. Volume of sample - This is a physical property because it can be measured directly and does not change the composition of the lead.
4. Melting point - This is a physical property since it involves changing physical states (solid to liquid) without changing the substance's chemical makeup.
5. Reaction with air - This is a chemical property because it describes a chemical reaction where lead forms lead oxide when reacting with air.
6. Electrical conductivity - This is a physical property as it describes the material's ability to conduct electricity without changing its fundamental chemical structure.

Based on this categorization, we have:

- Physical Properties: color, density, volume of sample, melting point, electrical conductivity (5 properties).
- Chemical Properties: reaction with air (1 property).

Count the number of physical and chemical properties:
- Physical properties: 5
- Chemical properties: 1

Now, let's determine the true statement:
1. The student investigated only the physical properties of lead. - This statement is false since there is also a chemical property investigated (`reaction with air`).
2. The student investigated only the chemical properties of lead. - This statement is false because physical properties were investigated (`color`, `density`, `volume of sample`, `melting point`, `electrical conductivity`).
3. The student investigated more physical properties than chemical properties of lead. - This statement is true because there are 5 physical properties and only 1 chemical property.
4. The student investigated more chemical properties than physical properties of lead. - This statement is false since the number of physical properties (5) is greater than the number of chemical properties (1).

Thus, the true statement is: The student investigated more physical properties than chemical properties of lead.