Student Activity

C3, Topic 3.7 Student activity

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Carbon blogging

Specification references:  C2.2.6 Giant covalent structures  C2.3.1 Diamond  C2.3.2 Graphite

Aims In this activity, you will compare the properties of two carbon-based giant covalent structures–diamond and graphite. You will write an article in the style of a blog post, in which you discuss the properties and uses of giant covalent structures.

Learning outcomes After completing this activity, you should be able to:  understand that giant covalent substances such as diamond, graphite, and silicon dioxide are solids with high melting points  explain the properties of diamond and graphite in terms of their structure and bonding.

Setting the scene Diamond and graphite are both made up of carbon atoms linked together by covalent bonds, forming a giant covalent structure. They behave differently to each other because the carbon atoms are arranged in different ways.

Task Use your knowledge about giant covalent structures to fill in the table, comparing diamond to graphite. Then, write a summary about diamond and graphite in the form of a blog post. In this you should include:  the key properties and features of each structure  uses of each structure based on their properties  a link to at least one interesting web page in which giant covalent carbon structures are discussed.

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Diamond Graphite Melting Point (high or low) Explanation

Hardness (hard or soft) Explanation

Electrical conductivity Explanation

Thermal conductivity Explanation

Main uses

Explanation

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Student follow up Answer the following questions on giant covalent structures. 1 Complete the following sentences with the correct number. In diamond, each carbon atom is covalently bonded to ______atoms. In graphite, each carbon atom is covalently bonded to ______atoms. (2)

2 Silicon dioxide is another example of a giant covalent substance. a Draw a small section of silicon dioxide and label the silicon and oxygen atoms and a covalent bond. (3)

b Silicon dioxide and sodium chloride (salt) are two components of sand. Suggest why: i silicon dioxide has a high melting point,

ii salt has a high melting point,

iii molten salt conducts electricity, but molten silicon dioxide doesn’t.