Important Questions: Materials: Metals And Non Metals - UPSC MCQ

Potassium is more reactive than Sodium and Lithium because Potassium is bigger than them. So outermost electron is farther away from nucleus. So the ionization energy in K is less than that in Na or in Li. So Potassium is more reactive than many other metals.

The correct option is A.
Liquid metal consists of alloys with very low melting points which form a eutectic that is liquid at room temperature. The standard metal used to be mercury, but gallium-based alloys, which are lower both in their vapor pressure at room temperature and toxicity, are being used as a replacement in various applications.

Seventeen elements are generally classified as nonmetals; most are gases (hydrogen, helium, nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton, xenon and radon); one is a liquid (bromine), and a few are solids (carbon, phosphorus, sulfur, selenium, and iodine).

Because sodium catches fire in normal air .

Metals that are liquids at room temperature are mercury (Hg) and gallium (Ga).

Non-metals liquid at room temperature - bromine (Br).

However, other elements such as caesium (Cs), rubidium (Rb) and francium (Fr) also become liquids at a few degrees above room temperature.

Classification of Materials:

Materials around us can be classified into:

A: Elements and compounds

- Elements are substances that cannot be broken down into simpler substances by chemical means.
- Compounds are substances that are made up of two or more elements chemically combined in fixed proportions.
- Examples of elements: oxygen, carbon, gold.
- Examples of compounds: water (H2O), salt (NaCl).

B: Metals and non-metals

- Metals are typically hard, shiny, and good conductors of heat and electricity.
- Non-metals are usually dull, brittle, and poor conductors of heat and electricity.
- Examples of metals: iron, copper, aluminum.
- Examples of non-metals: carbon, sulfur, oxygen.

C: Acids and bases

- Acids are substances that release hydrogen ions (H+) when dissolved in water and have a sour taste.
- Bases are substances that release hydroxide ions (OH-) when dissolved in water and have a bitter taste.
- Examples of acids: vinegar (acetic acid), lemon juice (citric acid).
- Examples of bases: baking soda (sodium bicarbonate), soap (sodium hydroxide).

D: None of these

- This option is incorrect as materials can indeed be classified into elements and compounds, metals and non-metals, or acids and bases.

Answer: B

- The correct classification of materials around us is into metals and non-metals.

Introduction:
Metals are a group of elements that are typically characterized by their shiny appearance, high electrical and thermal conductivity, and malleability. Most metals are solids at room temperature, but there are a few exceptions.
Body:
The given options are:
A: Sodium
B: Calcium
C: Mercury
D: Hydrogen
To determine which option is correct, we need to identify the state of each element at room temperature.
1. Sodium:
- Sodium is a metal and is typically a solid at room temperature. Therefore, it is not the correct answer.
2. Calcium:
- Calcium is also a metal and is typically a solid at room temperature. Therefore, it is not the correct answer.
3. Mercury:
- Mercury is a unique metal that is an exception to the general rule. It is the only metal that is a liquid at room temperature. Therefore, it is the correct answer.
4. Hydrogen:
- Hydrogen is not a metal; it is a nonmetal. Therefore, it is not the correct answer.
Conclusion:
In conclusion, all metals are solids except for Mercury, which is a liquid at room temperature. Therefore, option C, Mercury, is the correct answer.

Metal oxides are of nature
Metal oxides can exhibit different chemical properties depending on their composition and structure. However, in general, metal oxides are categorized as either acidic or basic.
Acidic nature of metal oxides:
- Some metal oxides, such as sulfur dioxide (SO2) and nitrogen dioxide (NO2), can react with water to form acidic solutions. These oxides are called acidic oxides.
- Acidic oxides release hydrogen ions (H+) when dissolved in water, which makes the solution acidic.
- Examples of acidic oxides include carbon dioxide (CO2), sulfur trioxide (SO3), and nitrogen trioxide (NO3).
Basic nature of metal oxides:
- Other metal oxides, such as sodium oxide (Na2O) and calcium oxide (CaO), can react with water to form basic solutions. These oxides are called basic oxides.
- Basic oxides release hydroxide ions (OH-) when dissolved in water, which makes the solution basic.
- Examples of basic oxides include magnesium oxide (MgO), sodium oxide (Na2O), and calcium oxide (CaO).
Neutral nature of metal oxides:
- Some metal oxides, such as aluminum oxide (Al2O3) and zinc oxide (ZnO), are amphoteric, meaning they can exhibit both acidic and basic properties depending on the reaction conditions.
- Amphoteric oxides can react with both acids and bases, and their behavior can vary depending on the specific reactants involved.
Conclusion:
- Metal oxides can be classified as acidic, basic, or amphoteric, depending on their chemical properties.
- The correct answer to the given question is Option B: Basic, as metal oxides are commonly known for their basic nature.

Sodium and potassium are soft metals. So an ordinary knife and a little pressure is enough to cut them.

Non-metals react differently with water compared to metals. Here is a detailed explanation of what happens when non-metals react with water:
1. Non-Metals Do Not React with Water:
- Non-metals generally do not react with water. They are not able to donate electrons to water molecules or displace hydrogen from water.
- This is because non-metals have high electronegativity, which means they have a strong attraction for electrons and tend to gain electrons rather than lose them.
2. Hydrogen Gas is Not Formed:
- Unlike metals, non-metals do not produce hydrogen gas when they react with water.
- Hydrogen gas is typically produced when metals react with water because metals have a tendency to lose electrons and form positive ions. These positive ions react with water, producing hydrogen gas.
3. Carbon Dioxide Gas is Not Formed:
- Carbon dioxide gas is also not formed when non-metals react with water.
- Carbon dioxide gas is produced when certain carbon-containing compounds react with water or when carbonates or bicarbonates react with acids. Non-metals, however, do not typically produce carbon dioxide gas in their reaction with water.
4. None of These:
- As mentioned earlier, non-metals do not react with water, and therefore, none of the given options (A: Hydrogen gas is formed, B: Carbon dioxide gas is formed) are correct.
- The correct answer is option C: Non-metals do not react with water.
In conclusion, non-metals do not react with water and do not produce hydrogen gas or carbon dioxide gas.

Explanation:
The property of metals by which they can be beaten into thin sheets is called malleability. Malleability is the ability of a material to be deformed under compression without fracturing. It is a desirable property in metals as it allows them to be shaped and formed into various shapes and structures.
Key Points:
- Malleability is a property of metals.
- It refers to the ability of a metal to be beaten or hammered into thin sheets.
- Malleability is a result of the metallic bonding in metals, which allows the atoms to slide past each other without breaking.
- Metals that have high malleability include gold, silver, and aluminum.
- Malleability is an important property in industries such as construction, manufacturing, and jewelry making.
- It allows metals to be easily formed into desired shapes and structures.
- Malleability is different from ductility, which refers to the ability of a material to be drawn into thin wires.
- Both malleability and ductility are important properties of metals and are a result of the metallic bonding in metals.

Non- metals  are non - (malleable and ductile). They are very brittle, and cannot be rolled into wires or poundes into sheets.

The correct option is B.
bromine is a fairly abundant element but has a rare property: it is the only nonmetal to exist in liquid form at room temperature, and one of only two elements (the other being mercury) that is liquid at room temperature and pressure.

Answer:
Property of Beating Metals into Thin Sheets:
- The property of beating metals into thin sheets is indeed called malleability.
- Malleability is the ability of a material, particularly a metal, to be hammered or rolled into thin sheets without breaking.
- Metals with high malleability can be easily shaped and formed into various shapes and structures.
- Malleability is an important property in metalworking and is utilized in processes such as forging, rolling, and stamping.
Proof of the Correct Answer:
- The statement in the question is true, as malleability is the correct term for the property described.
- Malleability is a well-known property of metals and is widely recognized in the field of materials science and engineering.
- The term malleability is used to describe the ability of metals to undergo plastic deformation under compressive stress, resulting in the formation of thin sheets or other desired shapes.
Conclusion:
- The property of beating metals into thin sheets is indeed called malleability.
- Therefore, the correct answer to the question is A: True.

The correct option is A.
 Oxides of metals are actually basic in nature not alkaline. This can be explained as oxygen reacts with metal to form corresponding metal oxides which are basic in nature. Also these metal oxides react with acid to form salt and water this shows that they are basic in nature.

Answer:

Statement: Metals are solid except mercury.

Explanation:
To determine the correctness of the given statement, let's analyze the properties of metals and mercury.
1. Metals:
- Most metals are solid at room temperature.
- They have high melting and boiling points.
- Examples of solid metals include iron, copper, aluminum, gold, etc.
2. Mercury:
- Mercury is the only metal that is liquid at room temperature.
- It has a low melting point of -38.83°C (-37.89°F) and a boiling point of 356.73°C (674.11°F).
- Due to its low melting point, mercury remains in a liquid state under normal atmospheric conditions.
Conclusion:
Based on the properties of metals and mercury, we can conclude that the statement is true. Metals are generally solid at room temperature, except for mercury, which is the only metal that exists in a liquid state.

True, because there are some non metals that are found in solid, liquid and gas. diamond is found in solid state form, bromine found in liquid state form and helium and oxygen are found in gas state.

Sodium and potassium metals reacts very vigorously with water ; this reaction gives out so much heat that the hydrogen evolved catches fire. Therefore, these metals are stored under kerosene .
So, the given statement is false.

Sodium is a soft metal that can be cut easily with a table knife. It is not a hard metal. Freshly cut sodium metal has a bright, shiny surface that quickly becomes a dull gray as it reacts with oxygen in the air around it.
So, the given statement is false.

The chlorine is a very reactive now metal. All noble gases are considered as non - metals.
So, the given statement that chlorine is a very reactive metal, is false.