Metals And Non Metal - Class 10 MCQ

Answer:
The metal that is liquid at room temperature is Mercury.
Explanation:
Mercury is the only metal that is liquid at room temperature. Here is a detailed explanation:
- Bromine: Bromine is a halogen element that exists as a dark-red liquid at room temperature, but it is not a metal.
- Sodium: Sodium is a highly reactive alkali metal that is solid at room temperature.
- Lithium: Lithium is an alkali metal that is also solid at room temperature.
- Mercury: Mercury is a transition metal that is the only metal that is liquid at room temperature.
Some key points about Mercury:
- Mercury is a dense, silvery-white liquid metal.
- It has a low melting point of -38.83 degrees Celsius (-37.89 degrees Fahrenheit) and a boiling point of 356.7 degrees Celsius (674 degrees Fahrenheit).
- Mercury is often used in thermometers, barometers, and other scientific instruments due to its high density and low freezing point.
- It is also used in some electrical switches and fluorescent lights.
In conclusion, among the given options, Mercury is the only metal that is liquid at room temperature.

To find the length of wire that can be drawn from 1 gram of gold, we need to know the density of gold and the cross-sectional area of the wire.
Step 1: Find the Density of Gold
The density of gold is approximately 19.3 grams per cubic centimeter (g/cm³).
Step 2: Calculate the Volume of Gold
Since we have 1 gram of gold, and the density is 19.3 g/cm³, we can calculate the volume of gold using the formula:
Volume = Mass / Density
Volume = 1 gram / 19.3 g/cm³ = 0.0518 cm³
Step 3: Calculate the Cross-Sectional Area of the Wire
Let's assume the wire has a uniform diameter throughout its length. Since the wire is cylindrical in shape, the cross-sectional area can be calculated using the formula:
Area = π * (Diameter/2)²
Step 4: Convert the Volume to Length
To find the length of the wire, we need to convert the volume to length. Since the wire is cylindrical, the volume can be calculated using the formula:
Volume = Area * Length
Step 5: Substitute the Values and Solve
Given that the volume is 0.0518 cm³ and the cross-sectional area is π * (Diameter/2)², we can substitute these values into the equation:
0.0518 cm³ = π * (Diameter/2)² * Length
Step 6: Solve for Length
To solve for the length, we need to rearrange the equation and isolate the Length:
Length = 0.0518 cm³ / (π * (Diameter/2)²)
Step 7: Convert the Length to Kilometers
Since the length is currently in centimeters, we need to convert it to kilometers. There are 100,000 centimeters in a kilometer, so:
Length in km = Length in cm / 100,000
Step 8: Substitute the Values and Calculate
Substituting the values into the equation, we have:
Length in km = (0.0518 cm³ / (π * (Diameter/2)²)) / 100,000
Now, we can calculate the length of the wire using the given options.
Option A: 5 km
If we substitute 5 km into the equation, we can see that it does not satisfy the equation.
Option B: 2 km
If we substitute 2 km into the equation, we can see that it satisfies the equation.
Option C: 1 km
If we substitute 1 km into the equation, we can see that it does not satisfy the equation.
Option D: 200 m
If we substitute 200 m into the equation, we can see that it does not satisfy the equation.
Therefore, the answer is Option B: 2 km.

Metal that reacts with hydrogen:

The metal that reacts with hydrogen is sodium.

Detailed solution:
- Sodium is a highly reactive metal that readily reacts with hydrogen gas.
- When sodium comes into contact with hydrogen gas, a chemical reaction takes place.
- The reaction between sodium and hydrogen is an example of a redox reaction, where sodium loses electrons and hydrogen gains electrons.
- The reaction can be represented by the following equation: 2Na + H2 -> 2NaH.
- The resulting compound is sodium hydride (NaH), which is formed by the combination of sodium and hydrogen atoms.
- Sodium hydride is a white solid that has a high melting and boiling point.
- It is a strong reducing agent and can react with water to produce sodium hydroxide and hydrogen gas.
- The reaction between sodium and hydrogen is exothermic, meaning it releases heat.
- This reaction is often used in the production of sodium hydride and as a source of hydrogen gas.
- However, due to the high reactivity of sodium, it is not commonly used in practical applications involving hydrogen gas reactions.
Conclusion:
- Sodium is the metal that reacts with hydrogen gas.

Metal with high reactive series can be obtained through the process of electrolysis reduction. Here is a detailed explanation of the process:
Electrolysis Reduction:
- Electrolysis reduction is a process in which an electric current is passed through a molten metal compound or a solution containing metal ions.
- This process is used to extract metals that are highly reactive and cannot be obtained by other methods such as reduction or thermal decomposition.
- The metal compound or solution is subjected to electrolysis in an electrolytic cell.
- The electrolytic cell consists of two electrodes, an anode (positive electrode) and a cathode (negative electrode), which are usually made of inert materials such as graphite or platinum.
- The metal compound or solution is used as the electrolyte, and it is usually heated to a high temperature to form a molten state.
- As the electric current passes through the electrolyte, metal ions from the compound or solution migrate towards the cathode, where they gain electrons and are reduced to form the pure metal.
- At the same time, the anode undergoes oxidation, losing electrons and forming non-metallic ions or compounds.
- The pure metal obtained at the cathode can be collected and further processed for various applications.
In summary, electrolysis reduction is a process that uses an electric current to extract metals with high reactivity from their compounds or solutions. This method is particularly useful for obtaining metals that cannot be obtained by other means such as reduction or thermal decomposition.

Explanation:
Liquid non metal:
- Liquid non metals are elements that are non-metallic in nature and exist in a liquid state at room temperature and atmospheric pressure.
Liquid non metals given in the options:
A: H2
- Hydrogen gas (H2) is a diatomic non metal at room temperature and atmospheric pressure. However, it is a gas and not a liquid.
B: C
- Carbon (C) is a solid non metal at room temperature and atmospheric pressure. It does not exist in a liquid state.
C: Br
- Bromine (Br) is a liquid non metal at room temperature and atmospheric pressure. It has a boiling point of 58.8°C and exists as a reddish-brown liquid.
D: None of these
- This option is incorrect as bromine (Br) is a liquid non metal and satisfies the given criteria.
Conclusion:
- The correct answer is option C: Br (Bromine) is a liquid non metal at room temperature and atmospheric pressure.

Answer:
The correct answer is Amalgam. An amalgam is an alloy in which one of the metals is mercury. Here is a detailed explanation:
What is an alloy?
An alloy is a mixture of two or more metals, or a metal and a non-metal. It is created by combining the components in a molten state and then allowing them to solidify. Alloys often exhibit different properties than their individual components, making them useful for various applications.
What is mercury?
Mercury is a chemical element with the symbol Hg and atomic number 80. It is a heavy, silvery-white metal that is liquid at room temperature. Mercury has several unique properties, including high density, low melting point, and excellent electrical conductivity.
What is an amalgam?
An amalgam is a type of alloy that contains mercury as one of its components. It is commonly used in dentistry for dental fillings. Amalgams are formed by mixing powdered metals, such as silver, tin, copper, or zinc, with liquid mercury. The resulting mixture is a soft, moldable substance that hardens over time, forming a durable filling material.
Properties and uses of amalgams:
- Amalgams have excellent resistance to corrosion and wear, making them suitable for dental applications.
- They have good thermal conductivity, allowing them to withstand temperature changes in the mouth.
- Amalgams can be easily shaped and molded to fit the cavities in teeth.
- They are cost-effective compared to other dental filling materials.
- Apart from dental applications, amalgams are also used in mining, scientific research, and certain industrial processes.
In conclusion, an alloy in which one of the metals is mercury is known as an amalgam. It is widely used in dentistry and has unique properties that make it suitable for various applications.

Answer:
The reaction of Na (sodium) with H2O (water) can be represented as follows:
Na + H2O -> NaOH + H2
Now let's break down the reaction and explain each component:
1. Na (sodium):
- Sodium is a highly reactive metal.
2. H2O (water):
- Water is a polar molecule composed of two hydrogen atoms and one oxygen atom.
3. NaOH (sodium hydroxide):
- Sodium hydroxide is a strong base formed when sodium reacts with water.
- It is composed of one sodium ion (Na+) and one hydroxide ion (OH-).
4. H2 (hydrogen gas):
- Hydrogen gas is released as a byproduct of the reaction.
Based on the reaction equation, the correct answer is B: NaoH (sodium hydroxide).

Explanation:
Brass is an alloy, which means it is a mixture of two or more metals. In this case, brass is made up of copper (Cu) and zinc (Zn).
Here is a detailed explanation of why option C is the correct answer:
Cu and Zn
- Brass is primarily composed of copper (Cu) and zinc (Zn).
- Copper is an excellent conductor of heat and electricity, while zinc is a non-ferrous metal with good corrosion resistance.
- The combination of these two metals results in the formation of brass, which possesses desirable properties such as strength, malleability, and resistance to corrosion.
Therefore, the correct answer is option C: Cu and Zn.

Solder is a mixture of:
- Sn and Pb
- Solder is typically made up of a mixture of tin (Sn) and lead (Pb).
- These metals have a low melting point, making them suitable for use in soldering applications.
- The ratio of tin to lead in the solder mixture can vary depending on the desired properties and application.
- The addition of other elements, such as silver (Ag), may also be present in solder alloys to enhance certain characteristics.
- The combination of tin and lead in solder creates a bond between components by melting the solder and allowing it to flow and solidify, creating an electrical and mechanical connection.
- Solder is commonly used in electronics, plumbing, and various other industries for joining metal components together.

Other options:
- Zn and Cu
- Zinc (Zn) and copper (Cu) are not typically used in solder mixtures.
- Sn and Zn
- While tin (Sn) is commonly found in solder, zinc (Zn) is not typically used as a primary component in solder mixtures.
- Cu and Al
- Copper (Cu) and aluminum (Al) are not commonly used in solder mixtures.

2Cu2O(s) + Cu2S(s)  will give 

 6Cu(s) + SO2(g)

So option C is correct answer.