Connect with a knowledgeable community and get your questions answered on IDNLearn.com. Discover reliable answers to your questions with our extensive database of expert knowledge.

The table shows approximate values of the properties of four unknown elements. A student wants to know if each element is a metal or nonmetal.

\begin{tabular}{|c|c|c|c|c|}
\hline
\begin{tabular}{c}
Unknown \\
Element
\end{tabular} & \begin{tabular}{c}
Density \\
[tex]$\left( g / cm ^3\right)$[/tex]
\end{tabular} & \begin{tabular}{c}
Melting \\
Point \\
[tex]$\left({ }^{\circ} C \right)$[/tex]
\end{tabular} & \begin{tabular}{c}
Boiling \\
Point \\
[tex]$\left({ }^{\circ} C \right)$[/tex]
\end{tabular} & \begin{tabular}{c}
Relative \\
Electrical \\
Conductivity \\
(silver [tex]$=100)$[/tex]
\end{tabular} \\
\hline 1 & 9 & 1085 & 2927 & 95 \\
\hline 2 & 2 & 115 & 445 & [tex]$\sim 0$[/tex] \\
\hline 3 & 5 & 938 & 2820 & [tex]$\sim 0$[/tex] \\
\hline 4 & 2 & 3500 & 4027 & [tex]$\sim 0$[/tex] \\
\hline
\end{tabular}

Which conclusion can be accurately made about one of the unknown elements based on the data?

A. Element 1 is a metal because of its high density and high electrical conductivity.

B. Element 2 is a nonmetal because of its low density and low melting point.

C. Element 3 is a metal because of its high boiling point and low electrical conductivity.

D. Element 4 is a nonmetal because of its high melting point and low density.


Sagot :

To determine which conclusion can be accurately made about one of the unknown elements based on the given data, we need to analyze each of the given statements:

1. Element 1:
- Density: 9 [tex]\( g/cm^3 \)[/tex]
- Melting Point: 1085 [tex]\(^{\circ}C \)[/tex]
- Boiling Point: 2927 [tex]\(^{\circ}C \)[/tex]
- Electrical Conductivity: 95

2. Element 2:
- Density: 2 [tex]\( g/cm^3 \)[/tex]
- Melting Point: 115 [tex]\(^{\circ}C \)[/tex]
- Boiling Point: 445 [tex]\(^{\circ}C \)[/tex]
- Electrical Conductivity: ~0

3. Element 3:
- Density: 5 [tex]\( g/cm^3 \)[/tex]
- Melting Point: 938 [tex]\(^{\circ}C \)[/tex]
- Boiling Point: 2820 [tex]\(^{\circ}C \)[/tex]
- Electrical Conductivity: ~0

4. Element 4:
- Density: 2 [tex]\( g/cm^3 \)[/tex]
- Melting Point: 3500 [tex]\(^{\circ}C \)[/tex]
- Boiling Point: 4027 [tex]\(^{\circ}C \)[/tex]
- Electrical Conductivity: ~0

Let's evaluate each conclusion:

- Conclusion A:
Element 1 is a metal because of its high density and high electrical conductivity.

Analysis:
- Element 1 does have a high density of 9 [tex]\( g/cm^3 \)[/tex].
- Its electrical conductivity is equally high at 95 (relative to silver = 100).
- Both these properties are characteristic of metals.

Therefore, Conclusion A can be accurately made about Element 1.

- Conclusion B:
Element 2 is a nonmetal because of its low density and low melting point.

Analysis:
- Element 2 does have a low density of 2 [tex]\( g/cm^3 \)[/tex].
- It also has a low melting point of 115 [tex]\(^{\circ}C \)[/tex].
- Both these properties are indicative of nonmetals.

Conclusion B is also valid.

- Conclusion C:
Element 3 is a metal because of its high boiling point and low electrical conductivity.

Analysis:
- Element 3 has a high boiling point of 2820 [tex]\(^{\circ}C \)[/tex].
- Metals generally have high boiling points but they do not have low electrical conductivity.
- Hence, this conclusion is incorrect, as low electrical conductivity is generally a property of nonmetals, not metals.

- Conclusion D:
Element 4 is a nonmetal because of its high melting point and low density.

Analysis:
- Element 4 has a high melting point of 3500 [tex]\(^{\circ}C \)[/tex] which is unusual for nonmetals.
- It has a low density of 2 [tex]\( g/cm^3 \)[/tex], which is typical for nonmetals.
- However, a high melting point is more characteristic of metals or metalloids, so this conclusion is questionable.

Therefore, the most accurate conclusion based on the data is Conclusion A: Element 1 is a metal because of its high density and high electrical conductivity.

So, the correct answer is:
1. Element 1 is a metal because of its high density and high electrical conductivity.