- What are metals? Explain their general properties.Metals are elements that are typically solid at room temperature (except for mercury) and have high electrical and thermal conductivity. They are malleable, meaning they can be hammered into thin sheets, and ductile, allowing them to be drawn into wires. Metals also have a shiny appearance, known as metallic luster, and are good conductors of heat and electricity. They have high density and high melting and boiling points. Most metals can react with acids to produce hydrogen gas and salts. Metals are generally hard, though some, like sodium and potassium, are soft. They tend to lose electrons during chemical reactions, forming positive ions. Metals are usually found in nature in the form of ores, which need to be extracted through various processes. Common examples of metals include iron, copper, and aluminum.
- What are non-metals? Discuss their properties.Non-metals are elements that typically lack the characteristics of metals. They can be solids, liquids, or gases at room temperature, with examples like carbon (solid), bromine (liquid), and oxygen (gas). Non-metals are generally poor conductors of heat and electricity, with the exception of graphite, a form of carbon. They are not malleable or ductile; instead, they tend to be brittle when solid. Non-metals have low densities and low melting and boiling points compared to metals. They can gain electrons during chemical reactions, forming negative ions. Non-metals may have a dull appearance and are often found in nature in free forms or as part of compounds. Common examples of non-metals include sulfur, nitrogen, and chlorine. Their reactions with metals often form ionic compounds.
- What are metalloids? Provide examples and their properties.Metalloids are elements that have properties intermediate between metals and non-metals. They are typically semiconductors of electricity, making them valuable in electronic applications. Metalloids can exhibit metallic luster but are brittle like non-metals. They have varying degrees of conductivity, allowing them to be used in alloys and in the production of glass and ceramics. Common examples of metalloids include silicon, germanium, and arsenic. Silicon, for instance, is widely used in computer chips due to its semiconducting properties. Metalloids can form covalent bonds with non-metals and metallic bonds with metals, which allows for a diverse range of chemical behavior. They generally have moderate melting and boiling points. Their unique properties make them essential in technology and materials science.
- How do metals and non-metals react with oxygen?Metals and non-metals react with oxygen in different ways, resulting in various types of oxides. Metals typically react with oxygen to form metallic oxides, which are usually basic in nature. For example, when magnesium burns in oxygen, it forms magnesium oxide, which can react with acids to produce salts and water. The reaction is often vigorous and exothermic, releasing a significant amount of heat. Non-metals, on the other hand, react with oxygen to form non-metallic oxides, which are often acidic or neutral. For instance, carbon reacts with oxygen to produce carbon dioxide, which can react with water to form carbonic acid. The nature of the oxide formed depends on the element reacting with oxygen and its oxidation state. Overall, these reactions play a crucial role in various environmental and industrial processes. Understanding these reactions helps in the study of combustion and respiration.
- What is the difference between ionic and covalent bonding?Ionic bonding occurs when atoms transfer electrons from one to another, resulting in the formation of positively and negatively charged ions. This type of bonding typically occurs between metals and non-metals. For example, sodium (a metal) loses an electron to become a positive ion, while chlorine (a non-metal) gains that electron to become a negative ion. The electrostatic attraction between these oppositely charged ions forms a strong ionic bond. In contrast, covalent bonding involves the sharing of electron pairs between atoms, usually between non-metals. For example, in a molecule of water (H₂O), each hydrogen atom shares electrons with the oxygen atom. Covalent bonds can be single, double, or triple, depending on the number of shared electron pairs. The resulting compounds have distinct properties, such as lower melting and boiling points compared to ionic compounds. Understanding these bonding types is fundamental to studying chemical reactions and compound formation.
- Explain the process of extraction of metals from ores.The extraction of metals from ores involves several steps, including mining, concentration, reduction, and purification. Initially, ores containing metals are mined from the earth, either through surface or underground mining methods. Once mined, the ores undergo concentration to remove impurities, which can be done through methods like froth flotation or magnetic separation. The concentrated ore then undergoes reduction, where the metal is extracted from its compound. This is typically achieved through chemical reactions using heat, carbon, or electrolysis, depending on the metal’s reactivity. For example, iron is extracted from its oxide ore (hematite) using carbon in a blast furnace. After extraction, further purification processes may be necessary to obtain pure metal, which can involve electrolytic refining. This entire process is crucial for obtaining metals in a usable form for various industrial applications. The efficiency and environmental impact of these methods are important considerations in metallurgy.
- What are some common uses of metals?Metals are widely used in various applications due to their unique properties. For example, aluminum is lightweight and resistant to corrosion, making it ideal for aircraft and packaging materials. Iron is primarily used in construction and manufacturing due to its strength and durability. Copper is an excellent conductor of electricity, making it essential for electrical wiring and components. Gold and silver are used in jewelry and electronics because of their corrosion resistance and aesthetic appeal. Metals like titanium are valued for their strength-to-weight ratio, making them suitable for aerospace applications. Additionally, alloys, such as stainless steel (a combination of iron, chromium, and nickel), are used in various industries for their enhanced properties. The versatility of metals enables their use in everyday items, from kitchen utensils to complex machinery. As technology advances, new applications for metals continue to emerge.
- What are some common uses of non-metals?Non-metals play essential roles in various applications across multiple fields. For instance, oxygen is vital for respiration in living organisms and is widely used in medical applications, including oxygen therapy. Nitrogen is used in fertilizers, explosives, and as an inert atmosphere in industrial processes. Carbon, in the form of graphite, is used in lubricants, batteries, and pencils, while diamond is prized for its hardness and used in cutting tools and jewelry. Sulfur is essential for producing sulfuric acid, a key industrial chemical, and is used in fertilizers and pharmaceuticals. Chlorine is used in water treatment to disinfect and purify drinking water, as well as in the production of various chemicals. Non-metals are also important in the formation of organic compounds, which are the basis of life. Understanding the uses of non-metals is crucial for both industrial and environmental applications. As research progresses, new applications for non-metals continue to be discovered.
- How do metals and non-metals differ in their physical properties?Metals and non-metals exhibit several distinct physical properties that differentiate them. Metals are typically solid at room temperature (except mercury) and have a shiny appearance known as metallic luster. They are malleable and ductile, allowing them to be shaped into thin sheets or drawn into wires. In contrast, non-metals can be solids, liquids, or gases and often have a dull appearance. Non-metals are generally brittle when solid and cannot be easily shaped or stretched. Metals tend to have high melting and boiling points, while non-metals usually have lower melting and boiling points. Additionally, metals are good conductors of heat and electricity, whereas non-metals are poor conductors (with the exception of graphite). The differences in these physical properties are a result of the atomic structure and bonding characteristics of metals and non-metals, influencing their behavior in various chemical reactions.
- Describe the reactivity of metals with water.
The reactivity of metals with water varies significantly among different metals. Alkali metals like lithium, sodium, and potassium react vigorously with water to produce hydrogen gas and metal hydroxides. For example, when sodium reacts with water, it forms sodium hydroxide and hydrogen gas, often resulting in an exothermic reaction that can ignite the hydrogen. These reactions are typically characterized by rapid fizzing and the release of heat. In contrast, alkaline earth metals like calcium also react with water, though less violently, producing hydroxides and hydrogen. Most transition metals, such as iron and copper, react with water very slowly or not at all, especially at room temperature. Iron may react with steam at high temperatures to produce iron oxide and hydrogen gas. The differences in reactivity are influenced by the metal’s position in the reactivity series, which ranks metals based on their tendency to lose electrons and form positive ions. Understanding metal reactivity with water is important for applications in chemistry and engineering.
Read Also: Top 10 Essential Q&A for ‘Class 10 Science Chapter 2 – Acids, Bases and Salt’ Part – 5
1 thought on “Top 10 Essential Q&A for ‘Class 10 Science Chapter 3 – Metals and Non-metals’ Part – 1”