Question

1. wekesa, a grade 8 learner, wants to know why the symbol for aluminium is al and the symbol for nitrogen is n. explain to wekesa how the chemical symbols have been derived.
2. gold, silver and copper are used in making jewellery.

a) state two reasons that make them suitable for making jewellery.
b) if one was to buy a wedding ring made of the three elements, which one will have the highest market value? give a reason for your answer.

1. iron is the most commonly used element in day - to - day life. state some of its applications.
2. you have been invited by members of the science club at your school to talk to them about the market value of common elements. briefly write what you will present in your exercise book.
3. a) identify the elements described below.

i) i am used in filling weather balloons. who am i? write my symbol.
ii) i am the most abundant component of air. who am i? write my symbol.

Explanation:

Step1: Explain chemical symbols origin

Chemical symbols are usually derived from the element's English or Latin name. Aluminium is from "aluminium" and its symbol is Al. Nitrogen is from "nitrogen" and its symbol is N. Some symbols come from Latin names, like Fe for iron (ferrum in Latin).

Step2: List reasons for jewellery - making elements

a) Gold, silver and copper are suitable for making jewellery because they are malleable (can be hammered into thin sheets), ductile (can be drawn into wires), and have an attractive luster.

Step3: Determine highest - value element

b) Gold will have the highest market value among the three. It is rarer than silver and copper, has high resistance to corrosion and is highly prized in various cultures for its beauty and status - symbol value.

Step4: List iron applications

Iron is used in construction (e.g., in steel - reinforced concrete for buildings and bridges), in making machinery parts, in vehicles (car frames, engine components), and in making tools.

Step5: Present on market value of elements

In a talk about the market value of common elements, one could present that elements like gold and platinum have high values due to their rarity, resistance to corrosion and high demand in jewellery and some industrial applications. Elements like iron and aluminium are more common and have lower market values per unit mass but are used in large quantities in construction and manufacturing.

Step6: Identify elements

a) i) The element used in filling weather balloons is helium (symbol He).
ii) The most abundant component of air is nitrogen (symbol N).

Step7: List uses of identified elements

Helium is used in filling balloons (due to its low density and non - flammability), in cryogenics (to cool superconducting magnets), and in leak detection. Nitrogen is used in the food industry for packaging (to prevent oxidation), in the production of ammonia for fertilizers, and in inert gas environments in some industrial processes.

Answer:

• Chemical symbols origin: Derived from English or Latin names.
• Jewellery - making reasons: Malleable, ductile, luster.
• Highest - value element: Gold, due to rarity, corrosion resistance and cultural value.
• Iron applications: Construction, machinery, vehicles, tools.
• Market value talk: High - value elements like gold, low - value but high - usage elements like iron.
• Identified elements: i) Helium (He), ii) Nitrogen (N).
• Uses of identified elements: Helium in balloons, cryogenics, leak detection; Nitrogen in food packaging, fertilizer production, inert gas environments.