Matter and Materials Quiz

Pure substances are composed of similar particles, while impure substances consist of different kinds of particles.

Elements are made of a single type of particle, whereas compounds consist of combinations of multiple elements.

Metals donate electrons readily, which defines their electropositive character.

<p>Graphite is a conductive non-metal, while sodium and potassium are soft metals.</p> Signup and view all the answers

<p>Most metals are solids, while non-metals can exist in solid, liquid, or gaseous states.</p> Signup and view all the answers

<p>Metals are good conductors of heat and electricity, while non-metals are poor conductors, with graphite as an exception.</p> Signup and view all the answers

<p>Metals are malleable, allowing them to be hammered into thin sheets, whereas non-metals are not malleable.</p> Signup and view all the answers

<p>Metals generally have high melting and boiling points, while non-metals typically have lower melting and boiling points.</p> Signup and view all the answers

<p>In an electrolytic cell, the electrodes facilitate the electrolysis process, where the anode is oxidized and the cathode is reduced. This differs from a galvanic cell, where the electrodes generate electric current from spontaneous chemical reactions.</p> Signup and view all the answers

<p>Electroplating involves using a metal object as a cathode while plating metal is dissolved at the anode, forming a thin layer of the plating metal on the object. Its primary purpose is to enhance appearance and provide corrosion resistance.</p> Signup and view all the answers

<p>Electrorefining purifies impure metals by using the impure sample as the anode and depositing pure metal onto the cathode. This process is significant as it enhances the purity and quality of metals for industrial applications.</p> Signup and view all the answers

<p>Anodizing creates a protective oxide layer on aluminum through electrolysis, typically in a sulfuric acid electrolyte, resulting in improved corrosion resistance and durability. This enhances both the aesthetics and functional lifespan of aluminum products.</p> Signup and view all the answers

<p>Alloying improves properties like corrosion resistance, strength, and durability; for example, steel, made from iron and carbon, exhibits enhanced strength and hardness over pure iron. This illustrates how alloying can significantly alter the characteristics of base metals.</p> Signup and view all the answers

<p>Metals typically have 1-3 valence electrons and are electron donors, forming positive ions, while non-metals have 4-8 valence electrons, act as electron acceptors, and form negative ions.</p> Signup and view all the answers

<p>Amphoteric oxides like aluminum oxide can react with acids to form salts and water, and with bases to also form salts and water.</p> Signup and view all the answers

<p>The general reaction is Metal + Water → Metal Oxide + Hydrogen + Heat, while with excess water, it leads to Metal Oxide + Water → Metal Hydroxide + Hydrogen.</p> Signup and view all the answers

<p>The position is determined by its reactivity level, with more reactive metals at the top and less reactive metals at the bottom.</p> Signup and view all the answers

<p>Ionic compounds are solid at room temperature, have high melting and boiling points, and are soluble in water but insoluble in organic solvents.</p> Signup and view all the answers

<p>Metallurgy encompasses the methods and processes involved in extracting metals from their ores found in the Earth's crust.</p> Signup and view all the answers

<p>Roasting involves heating ores in the presence of oxygen to remove sulfur, while calcination is heating in the absence of oxygen, primarily for carbonate ores.</p> Signup and view all the answers

<p>Electrolysis is used to purify metals by depositing pure metal at the cathode while impurities fall to the bottom as anode mud.</p> Signup and view all the answers

<p>Rusting is an electrochemical process where iron oxidizes in the presence of air and water, forming hydrated iron oxide, represented as Fe2O3.xH2O.</p> Signup and view all the answers

<p>Effective methods include painting, oiling/greasing, galvanization, and chromium plating to isolate iron from moisture and air.</p> Signup and view all the answers

<p>Metals react with dilute acids to form salts and hydrogen gas; however, nitric acid does not release hydrogen gas with most metals due to its strong oxidizing nature.</p> Signup and view all the answers

<p>Non-metal oxides are generally acidic in nature and are formed when non-metals react with oxygen.</p> Signup and view all the answers

<p>In electrolysis, the anode serves as the positive electrode where oxidation occurs, and the cathode is the negative electrode where reduction takes place.</p> Signup and view all the answers

<p>Gangue particles are impurities mixed with ores that must be removed during the ore concentration process.</p> Signup and view all the answers