Questions and Answers
Which of the following reactions generates sulfur dioxide gas?
Which statement correctly describes the reactivity of non-metals with acids?
What is a characteristic property of metalloids?
Which metal does not liberate sulfur dioxide when reacting with hot concentrated sulfuric acid?
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Which of the following metalloids is known for its good conductivity at elevated temperatures?
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Which of the following reactions illustrates a base-induced reaction involving metals?
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What defines the location of metalloids on the periodic table?
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Which of the following compounds is formed when aluminum reacts with concentrated bases?
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Which non-metal does not typically react with acids?
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What happens to the conductivity of metalloids with an increase in temperature?
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Study Notes
Classification of Elements
- Elements are classified as metals, non-metals, and metalloids, based on various properties.
Properties of Metals
- Generally solid at room temperature, with exceptions like mercury (Hg) and gallium (Ga) being liquids.
- High melting and boiling points, though sodium (Na), potassium (K), and mercury (Hg) have lower points.
- Typically hard, but exceptions include sodium (Na) and potassium (K), which are soft.
- High density, except for lithium (Li), sodium (Na), and potassium (K), which are less dense than water.
- Good conductors of heat and electricity; exceptions include bismuth (Bi) and tungsten (W).
- Possess lustre, giving metallic shine.
- High tensile strength, although zinc (Zn) has very low tensile strength.
- Generally malleable and ductile, with zinc being an exception.
- Sonorous, producing a ringing sound when struck.
- Found primarily in combined states, with noble metals being the exception occurring in free state.
Properties of Non-Metals
- Mostly gaseous at room temperature, with solids like carbon (C), sulfur (S), phosphorus (P), iodine (I2), and bromine (Br) existing in various states.
- Characterized by low melting and boiling points; exceptions include carbon (C), silicon (Si), and boron (B).
- Solid non-metals are generally brittle, with diamond being the hardest naturally occurring substance.
- Low density in general, with diamond being an exception.
- Poor conductors of heat and electricity; graphite and gas carbon act as good conductors.
- Lack lustre, although iodine (I2) and graphite have some.
- Non-malleable and non-ductile, except for ductile carbon fibers.
- Non-sonorous.
- Found in both free and combined states.
Valence Electrons and Ionic Formation
- Metals contain 1 to 3 electrons in their valence shells, allowing them to lose electrons and form stable cations.
- Non-metals have 4 to 7 electrons in their valence shells, typically gaining electrons to form stable anions.
Reactions with Oxygen
- Metals react with oxygen to form basic metal oxides, which turn red litmus blue.
- Non-metals form acidic oxides, turning blue litmus red.
- Examples: Sodium (Na) and potassium (K) react vigorously with oxygen; carbon (C) and sulfur (S) produce carbon dioxide and sulfur dioxide, respectively.
Reactions with Water
- Potassium and sodium react vigorously with cold water, producing alkali solutions and hydrogen gas.
- Most non-metals do not react with water; exceptions include carbon producing water gas when reacted with steam.
Reactions with Acids
- Active metals (like Mg and Zn) react with dilute hydrochloric acid (HCl) and sulfuric acid (H2SO4), releasing hydrogen gas.
- Very few non-metals react with acids; sulfur (S) and carbon (C) exhibit reactions with concentrated sulfuric acid.
Reactions with Bases
- Metals such as aluminium (Al) and zinc (Zn) react with concentrated bases to produce hydrogen gas.
- Non-metal reactivity with bases is more complex and less common.
Metalloids
- Exhibit properties of both metals and non-metals.
- Notable metalloids include germanium, arsenic, antimony, selenium, and tellurium, each possessing unique conductive and chemical properties.
Location in the Periodic Table
- Metals are predominantly on the left side, non-metals are on the right, and metalloids are situated in a staircase pattern between them.
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Description
Test your knowledge on the classification of elements into metals, non-metals, and metalloids. This quiz covers their properties and characteristics to help you understand their distinctions better.
