Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
17 Cards in this Set
- Front
- Back
|
What are atoms?
|
The smallest particle that can take part in a chemical reaction.
|
|
|
What are molecules?
|
Particles made of two or more atoms chemically joined together.
|
|
|
What is ionic bonding?
|
The transferring of electrons; always between a metal and a non-metal.
|
|
|
What is covalent bonding?
|
The sharing of electrons; always between two non-metals.
|
|
|
Describe the stages of the Limestone Cycle.
|
1. Starting as calcium carbonate , it is thermally decomposed. This releases CO2 into the atmosphere and therefore makes carbon oxide (quicklime).
2. When water is added to quicklime, calcium hydroxide (slaked lime) is produced. 3. By adding more water and filtering, a calcium hydroxide solution (lime water) is made. 4. Putting CO2 into the solution returns back to the start of the cycle with the calcium carbonate. |
|
|
What is mortar?
|
A workable paste used to bind construction blocks together and fill the gaps between them.
|
|
|
What is cement?
|
A binder: a substance that sets and hardens independently and can bind other materials together.
|
|
|
What is concrete?
|
A composite construction/building material composed of aggregate (stones and rocks), cement and water.
|
|
|
What is an ore?
|
A metal that is combined with other elements that can be extracted in economically viable amounts.Not all metals are combined with others - they;re described as in their native state.
|
|
|
How are metals low in the reactivity series extracted?
|
Metals such as copper (Cu) and silver (Ag) are either extracted by roasting an ore or occur in their native form.
|
|
|
How are metals in the middle of the reactivity series extracted?
|
Metals below carbon (on the Chemistry data sheet) like zinc (Zn) and iron (Fe) are extracted by reduction of the oxide with carbon or carbon monoxide.
|
|
|
How are metals high in the reactivity series extracted?
|
Reactive metals like aluminium (Al) and sodium (Na) are extracted using electrolysis.
|
|
|
Give five reasons for making alloys.
|
- To increase the strength or hardness of a metal.
- To change the colour. - Stop it from rusting/corroding. - Improved appearance.- To lower the boiling point of the metal. |
|
|
Describe low carbon steel.
|
Strong but brittle. Used for car bodies, containers and structural girders.
|
|
|
Describe high carbon steel.
|
Resistant to stretching. Used in suspension bridges and tools.
|
|
|
How does phytomining work?
|
Phytomining is used to extract copper by planting special crops in an area with low levels of copper in it. They concentrate the copper compounds into their shoots and other parts of the plant, which are then burned to produce ash containing the copper compounds.The ash is treated with acid to form a solution and electrolysed, collecting copper at the negative electrode.
|
|
|
How does bioleaching work?
|
Uses bacteria rather than plants; it is a much slower process than phytomining. Waste is sprayed over beds of bacteria which absorb copper compounds. The bacteria use the minerals attached to copper and the copper dissolves into the water.This can then be electrolysed or displaced.
|
