Question

Which of the following substances would you expect to possess metallic properties: (a) \(\mathrm{TiCl}_{4}\), (b) NiCo alloy, (c) \(\mathrm{W},(\mathrm{d})\) Ge, (e) \(\mathrm{ScN}\) ?

Short answer

The substances that are expected to possess metallic properties are (b) NiCo alloy and (c) \(\mathrm{W}\) (tungsten).

Step-by-step solution

List the given substances

We have the following substances: (a) \(\mathrm{TiCl}_{4}\) (b) NiCo alloy (c) \(\mathrm{W}\) (d) Ge (e) \(\mathrm{ScN}\)

Analyze each substance

(a) \(\mathrm{TiCl}_{4}\): This is a molecular compound formed by the combination of titanium (Ti, a metal) and chlorine (Cl, a non-metal). Since it is a compound and not a pure metal, it is not likely to possess metallic properties. (b) NiCo alloy: This is an alloy formed by combining nickel (Ni) and cobalt (Co), both of which are metallic elements. Since alloys typically retain the metallic properties of their constituent elements, we can expect NiCo alloy to possess metallic properties. (c) \(\mathrm{W}\): This is tungsten (W), a pure metal. As a metal element, it possesses metallic properties. (d) Ge: This is germanium (Ge), a metalloid. Metalloids have properties that are intermediate between those of metals and non-metals, and while they may possess some metallic properties, they generally lack the full range of metallic attributes. (e) \(\mathrm{ScN}\): This is a molecular compound formed by the combination of scandium (Sc, a metal) and nitrogen (N, a non-metal). Similar to \(\mathrm{TiCl}_{4}\), it is not likely to possess metallic properties since it is a compound and not a pure metal.

Identify the substances with metallic properties

Based on our analysis, the following substances possess metallic properties: (b) NiCo alloy (c) \(\mathrm{W}\) In conclusion, substances (b) NiCo alloy and (c) \(\mathrm{W}\) are expected to possess metallic properties, while the other options do not have the typical metallic attributes.

Key concepts

Compounds and Elements

In the realm of chemistry, it's crucial to differentiate between compounds and elements as they form the basis of all matter. Elements are pure substances consisting of only one kind of atom and are defined by the number of protons in their nucleus. Examples include hydrogen (H), oxygen (O), and tungsten (W), the latter being a metal and possessing metallic properties such as conductivity, malleability, and luster.
On the other hand, compounds are substances formed when two or more different elements are chemically bonded. An example is \(\mathrm{TiCl}_{4}\), which consists of titanium and chlorine. Since \(\mathrm{TiCl}_{4}\) is a compound and not a pure metal, it lacks the characteristic metallic properties of its metallic component, titanium. Compounds can be molecular, like \(\mathrm{TiCl}_{4}\) and \(\mathrm{ScN}\), indicating a level of variability in their attributes depending on the elements involved.

Alloys

Alloys are fascinating mixtures composed typically of two or more metallic elements, designed to enhance specific material properties. The NiCo alloy, a combination of nickel (Ni) and cobalt (Co), is a perfect example. Alloys possess metallic properties because their primary components are metals.
By mixing metals, a new material is created that often exhibits superior qualities compared to the pure metals on their own.

• For instance, increased strength and durability can be achieved by forming an alloy.
• They may also offer resistance to corrosion.

These valuable attributes make alloys essential in engineering and manufacturing, providing flexibility in designing materials for specific applications, while retaining basic traits such as conductivity and luster.

Metalloids

Metalloids are intriguing elements with characteristics that straddle the boundary between metals and non-metals. Germanium (Ge), for example, is a metalloid with a unique set of properties.

• It can exhibit some metallic qualities, such as its ability to conduct electricity under certain conditions.
• However, unlike pure metals, it does not have the full array of metallic traits like high luster or ductility.

This duality allows metalloids to be versatile, finding applications in fields like electronics where they function as semiconductors.
Their intermediate properties make metalloids crucial for understanding the spectrum of properties between metals and non-metals, although they often do not fit neatly into either category.

Molecular Compounds

Molecular compounds, such as \(\mathrm{TiCl}_{4}\) and \(\mathrm{ScN}\), are composed of non-metal elements bonded together, often by covalent bonds. These compounds are fundamental in chemistry due to their variety and range of properties.

• Typically, they do not conduct electricity well because they lack free-moving electrons.
• Unlike metallic structures, they are not malleable or ductile.

Their properties contrast sharply with those of metals and alloys, helping to underscore the differences between categories like molecular compounds and metallic elements. Understanding molecular compounds involves thinking about the distinct ways atoms can combine and the diverse results these combinations yield, making chemistry a rich field of study.