Which s-block element is a silvery-white metal that is used in an alloy with copper or nickel to make gyroscopes, springs, electrical contacts, spot-welding electrodes, and non-sparking equipment?
Beryllium
Identifying the S-Block Element for Specialized Uses
The question asks us to identify a specific s-block element based on its physical properties and industrial applications, particularly in alloys used for components like gyroscopes, springs, electrical contacts, spot-welding electrodes, and non-sparking equipment. Let's examine the characteristics of the s-block elements provided in the options.
Understanding S-Block Elements
S-block elements are those in which the last electron enters the outermost s-orbital. These are the elements of Group 1 (alkali metals) and Group 2 (alkaline earth metals) of the periodic table.
Analyzing the Options
We need to consider the properties and common uses of Rubidium, Beryllium, Caesium, and Francium.
- Rubidium (Rb): This is an alkali metal (Group 1). Alkali metals are very reactive, soft, low melting point metals. Rubidium is silvery-white but is primarily used in fireworks for a reddish-violet color and in some vacuum tube applications. It is not typically used in structural alloys for the applications mentioned due to its high reactivity and softness.
- Beryllium (Be): This is an alkaline earth metal (Group 2). Beryllium is a silvery-white metal known for being relatively light, strong, rigid, and having a high melting point. A key characteristic is its ability to form alloys, particularly with copper (beryllium copper). Beryllium copper alloys are famous for their strength, elasticity, thermal and electrical conductivity, and importantly, they are non-sparking and non-magnetic. These properties make them ideal for the uses listed in the question.
- Caesium (Cs): This is also an alkali metal (Group 1). It is extremely reactive, even more so than Rubidium, with a very low melting point (it's liquid near room temperature). Caesium is primarily used in atomic clocks and photoelectric cells. It is not used in alloys for the applications described.
- Francium (Fr): This is an alkali metal (Group 1) and is highly radioactive. It exists only in trace amounts and has a very short half-life. It has no significant practical commercial uses.
Beryllium: The S-Block Element for Specific Alloys
Based on the analysis, Beryllium stands out because its alloys, especially beryllium copper, exhibit the exact combination of properties and are used in the applications mentioned in the question. Beryllium copper alloys are utilized for:
- Gyroscopes: Due to their strength and elasticity.
- Springs: Excellent spring properties and fatigue resistance.
- Electrical Contacts: High electrical conductivity combined with strength and corrosion resistance.
- Spot-Welding Electrodes: Good electrical and thermal conductivity and resistance to wear.
- Non-Sparking Equipment: Crucial for tools and components used in potentially explosive environments (like oil rigs, mines) where sparks could ignite flammable materials.
Therefore, the s-block element described is Beryllium.
| Element | Block | Group | Typical Properties | Common Uses Relevant to Question |
|---|---|---|---|---|
| Rubidium (Rb) | s | 1 (Alkali Metal) | Soft, highly reactive, low melting point | Fireworks, vacuum tubes (Not alloys for listed uses) |
| Beryllium (Be) | s | 2 (Alkaline Earth Metal) | Strong, light, high melting point, forms alloys | Alloys (especially Be-Cu) for springs, contacts, non-sparking tools, etc. (Matches description) |
| Caesium (Cs) | s | 1 (Alkali Metal) | Extremely reactive, very low melting point | Atomic clocks, photoelectric cells (Not alloys for listed uses) |
| Francium (Fr) | s | 1 (Alkali Metal) | Highly radioactive, rare | No commercial uses |
Revision Table: Key S-Block Element Characteristics
| Group | Name | Key Characteristics |
|---|---|---|
| Group 1 | Alkali Metals (Li, Na, K, Rb, Cs, Fr) | Soft, highly reactive, low melting/boiling points, form +1 ions, vigorous reaction with water. |
| Group 2 | Alkaline Earth Metals (Be, Mg, Ca, Sr, Ba, Ra) | Harder than alkali metals, less reactive but still reactive, higher melting/boiling points, form +2 ions, react with water (less vigorously than Group 1, except for lighter members). |
Additional Information: Beryllium Copper Alloys
Beryllium copper (BeCu), also known as copper beryllium (CuBe), is a copper alloy containing 0.5–3% beryllium. The addition of beryllium significantly increases the strength and hardness of copper, while also improving its electrical and thermal conductivity compared to pure copper. Its excellent mechanical properties combined with conductivity and non-sparking characteristic make it indispensable in many critical applications, particularly in harsh or sensitive environments.
Important Questions from s - Block
Consider the following reaction scheme and the related statements.
BrF \(\stackrel{\text { disproportionation }}{\longrightarrow}\) Br2(g) + X (T-shaped geometry)
X \(\stackrel{\text { self ionization }}{\longrightarrow}\) Y (cation) + Z (anion)
A. X, Y, and Z have the same number of lone pairs of electrons.
B. Y has a bent shape.
C. Z is sp3 hybridized and has a tetrahedral shape.
D. X is used as a non-aqueous solvent.
The correct statements are
From which Latin word is the s block element calcium derived?
