Photo AI
This question is about oxygen and substances containing oxygen - AQA - GCSE Chemistry - Question 3 - 2017 - Paper 1
Question 3
This question is about oxygen and substances containing oxygen. 3 (a) (i) Complete Figure 4 to show the arrangement of the outer shell electrons in an oxygen molecu... show full transcript
Worked Solution & Example Answer:This question is about oxygen and substances containing oxygen - AQA - GCSE Chemistry - Question 3 - 2017 - Paper 1
Step 1
Complete Figure 4 to show the arrangement of the outer shell electrons in an oxygen molecule.
Answer
In Figure 4, the electron arrangement in an oxygen molecule (O₂) can be represented with two bonding pairs shared between the two oxygen atoms. Represent one oxygen atom's electrons with dots (•) and the other atom's electrons with crosses (×), resulting in:
• • • •
•• ••
This shows that each oxygen atom contributes two electrons, creating a double bond.
Step 2
Step 3
Explain why oxygen has a low boiling point.
Answer
Oxygen has a low boiling point due to weak intermolecular forces between its molecules. These weak forces require little energy to overcome, thus allowing oxygen to remain in a gaseous state at lower temperatures. Additionally, because oxygen is a small, simple molecule, it has fewer interactions with surrounding molecules, contributing to its low boiling point.
Step 4
Step 5
Describe what happens, in terms of electrons, when magnesium atoms react with oxygen atoms to produce magnesium oxide.
Answer
When magnesium atoms react with oxygen atoms, magnesium loses two electrons, resulting in the formation of magnesium ions (Mg²⁺), while oxygen gains two electrons to become oxide ions (O²⁻). This transfer of electrons leads to the formation of ionic bonds between these oppositely charged ions, creating magnesium oxide.
Step 6
What are nanoparticles?
Answer
Nanoparticles are particles that range from 1 to 100 nanometers in size. They typically contain a few hundred atoms and have a high surface area to volume ratio. This unique characteristic allows them to have distinct physical and chemical properties compared to larger particles.
Step 7
Explain, in terms of structure and bonding, why silicon dioxide is used to line furnaces.
Answer
Silicon dioxide (SiO₂) has a high melting point because of its strong covalent bonds and giant molecular structure. Each silicon atom is bonded to four oxygen atoms, forming a three-dimensional network. This structure requires a significant amount of energy to break these strong bonds, which makes silicon dioxide suitable for lining furnaces that operate at high temperatures, such as the 1500 °C in the given furnace.