Class X Science: Metals and Non-Metals - Properties, Occurrence, and Extraction

Flashcards covering properties of ionic compounds, occurrence of metals, definitions of ores and minerals, specific metal ores, and metallurgical processes.

Why does solid $NaCl$ fail to conduct electricity, while molten $NaCl$ and aqueous $NaCl$ solution conduct electricity?

In solid $NaCl$, ions are fixed in a rigid structure and cannot move. In the molten state, heat breaks the electrostatic forces so ions move freely, and in aqueous solution, ions dissociate and move to opposite electrodes.

Why is an ionic compound chosen over a covalent molecular compound for the inner lining of a high-temperature furnace?

Ionic compounds have strong electrostatic forces of attraction between oppositely charged ions, giving them high melting points and making them suitable for high-temperature applications.

How do ionic compounds behave when pressure is applied to them?

They are generally brittle and break into pieces when pressure is applied.

What are the solubility characteristics of ionic compounds in water versus organic solvents?

Ionic compounds are generally soluble in water, but insoluble in organic solvents such as petrol and kerosene.

How do metal atoms and non-metal atoms achieve stability regarding valence electrons and ion formation?

Metals typically have 1 to 3 valence electrons and lose them easily to form positive ions (cations), while non-metals typically have 5 to 7 valence electrons and gain electrons easily to form negative ions (anions).

What is the most abundant element and the most abundant metal in the Earth's crust?

Oxygen is the most abundant element, and aluminium is the most abundant metal (and the third most abundant element overall after oxygen and silicon) in the Earth's crust.

What are the two most abundant elements in the universe according to the lecture?

Hydrogen is the most abundant element in the universe, followed by Helium.

What is the key distinction between a mineral and an ore?

Minerals are naturally occurring elements or compounds in the Earth's crust, whereas ores are minerals that contain a sufficient amount of metal such that the metal can be extracted profitably.

What is the chemical formula and ore type of Bauxite?

Bauxite has the chemical formula $Al_2O_3 \times 2H_2O$ and is a hydrated oxide ore of aluminium.

What are the chemical formulas of the iron ores Haematite and Magnetite?

Haematite is $Fe_2O_3$ and Magnetite is $Fe_3O_4$, both of which are oxide ores.

What is the ore name and chemical formula for the sulphide ore of Mercury?

Cinnabar, with the chemical formula $HgS$.

What are the chemical formulas and ore kinds of Calamine and Zinc blende (Sphalerite)?

Calamine is a carbonate ore with formula $ZnCO_3$, and Zinc blende (Sphalerite) is a sulphide ore with formula $ZnS$.

What is the ore name, kind of ore, and chemical formula for the primary lead ore listed?

Galena is a sulphide ore of lead with the chemical formula $PbS$.

What is gangue in metallurgy?

Gangue refers to unwanted impurities like sand, clay, and rocky materials found along with ores.

What are the first two steps in the metallurgical extraction process?

Step 1 is Crushing and Grinding of Ore (to make extraction easier and more efficient), and Step 2 is Concentration of Ore / Enrichment (removing gangue to increase the percentage of metal).

How are high reactivity metals like $K$, $Na$, $Ca$, $Mg$, and $Al$ extracted from their concentrated ores?

They are extracted by electrolysis of their molten ore.

How are medium reactivity metals like $Zn$, $Fe$, and $Pb$ extracted from their oxide ores?

They are extracted by reduction using carbon ($C$), carbon monoxide ($CO$), or displacement.

A mining company finds mineral P (high metal content, low extraction cost), mineral Q (high metal content, very high extraction cost), and mineral R (low metal content, low extraction cost). Which mineral is an ore, and why?

Mineral P is the ore because a mineral must allow the metal to be extracted both conveniently and profitably/economically.

Why is Mineral C ($SiO_2$) not considered an ore in commercial extraction?

Mineral C is silica ($SiO_2$) and does not contain a metal that can be extracted economically.

Why are metals like sodium and potassium never found in the free (native) state in nature?

Sodium and potassium are highly reactive metals that readily combine with oxygen, moisture, and other substances to form compounds.