Covalent bondingIB MYP Chemistry: Mind map

Exam questions on Covalent bonding

1. A biogas plant in Kerala produces methane, CH₄, from rotting plant waste. The methane is burned for cooking. Carbon atoms have four electrons in their outer shell and hydrogen atoms have one.
   Describe how a covalent bond forms between a carbon atom and a hydrogen atom.2 marks
2. A scientist studying greenhouse gases examines carbon dioxide, CO₂, which forms when fossil fuels burn. Carbon atoms have four electrons in their outer shell and oxygen atoms have six.
   Explain how the atoms in a molecule of carbon dioxide each end up with a full outer shell.2 marks
3. A student uses a molecular model kit to compare molecules of methane (CH₄), ammonia (NH₃) and water (H₂O). Carbon atoms have four outer electrons, nitrogen atoms five and oxygen atoms six. She records how many hydrogen atoms attach to the central atom of each molecule.
   Describe the pattern in her results and use it to predict the number of hydrogen atoms that attach to a fluorine atom, which has seven outer electrons.3 marks