Classification of Elements Quiz

Study Notes

Elements are classified as metals, non-metals, and metalloids, based on various properties.

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.

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.

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.

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.

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.

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.

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.

Exhibit properties of both metals and non-metals.
Notable metalloids include germanium, arsenic, antimony, selenium, and tellurium, each possessing unique conductive and chemical properties.