2 Atoms, elements and compounds

Practice questions on Atoms, elements and compounds

• Explain why most metals have high densities and why alloying a metal with another element … (4 marks, Explain)
• Explain why metals have high melting points and are malleable (can be bent and shaped with… (4 marks, Explain)
• Graphite and diamond are both giant covalent structures made entirely of carbon atoms, yet… (4 marks, Explain)
• Compare the electrical conductivity of graphite and diamond, and explain the difference in… (4 marks, Compare)
• Describe the structure and bonding in diamond, and explain why diamond does not conduct el… (4 marks, Describe and Explain)
• Oxygen exists as simple molecules, O₂. Describe the bonding within an oxygen molecule and … (4 marks, Describe and Explain)
• Explain why ammonia (NH₃) has a low boiling point and does not conduct electricity when it… (4 marks, Explain)
• Calcium fluoride is an ionic compound containing calcium ions and fluoride ions. Describe … (4 marks, Describe and Explain)
• Uranium has two naturally occurring isotopes: uranium-235 and uranium-238. Explain why the… (4 marks, Explain)
• Chlorine has two naturally occurring isotopes: chlorine-35 and chlorine-37. Explain why th… (4 marks, Explain)
• Explain how the number of protons, neutrons and electrons in an atom determines its atomic… (4 marks, Explain)
• Describe the differences between an element, a compound, and a mixture. Include one exampl… (4 marks, Describe)
• State and explain why salt dissolved in water is classified as a mixture rather than a com… (4 marks, State and explain)
• Explain the difference between a compound and a mixture, using the properties of each to s… (4 marks, Explain)
• Copper sulfate is a compound. Describe four ways in which a compound differs from a mixtur… (4 marks, Describe)
• A student heats iron filings and sulfur powder together. After heating, a new grey solid i… (4 marks, Explain)
• Carbon-12 and carbon-14 are both isotopes of carbon. Explain why carbon-12 and carbon-14 h… (4 marks, Explain)
• Hydrogen has three isotopes: protium (hydrogen-1), deuterium (hydrogen-2), and tritium (hy… (4 marks, Explain)
• Magnesium oxide is an ionic compound. Explain why magnesium oxide has a high melting point… (4 marks, Explain)
• Neon exists as three naturally occurring isotopes: neon-20, neon-21, and neon-22. State wh… (4 marks, State and Describe)