The Periodic Table
State how elements are arranged in the Periodic Table.
An element is in Period 3, Group 7 of the Periodic Table. What is its electronic configuration?
An element has the electronic configuration 2,8,4. Determine its group and period number.
Describe how electrical conductivity can be used to classify an unknown element as a metal or a non-metal.
An element forms an oxide that dissolves in water to produce an acidic solution. Which classification and position in the Periodic Table is correct for this element?
Magnesium oxide reacts with hydrochloric acid. What does this reaction tell you about the nature of magnesium oxide?
Which statement correctly describes the terms ‘group’ and ‘period’ in the Periodic Table?
Explain why lithium and sodium have similar chemical properties.
A student claims that all non-metals are electrical insulators. Identify which substance disproves this claim and explain why.
Argon has the electronic configuration 2,8,8. Explain why argon does not readily react.
Helium has only 2 electrons yet is placed in Group 0 alongside elements with 8 outer electrons. Which explanation correctly justifies helium’s placement?
A scientist discovers a new element. It is a poor conductor of electricity and its oxide turns universal indicator red when dissolved in water. Which conclusion is correct?
Carbon dioxide dissolves in water to form carbonic acid: CO₂(g) + H₂O(l) → H₂CO₃(aq). What does this reaction demonstrate about the classification of carbon?
An element in Period 2 has similar chemical properties to phosphorus (2,8,5). Identify this element’s electronic configuration.
Which statement correctly explains why noble gases are monatomic?
A deep-sea diver breathes a gas mixture containing helium instead of nitrogen to prevent decompression sickness. Which property of helium makes it suitable for mixing with breathing gases in this context?
Potassium (2,8,8,1) reacts more vigorously with water than sodium (2,8,1). Both are in Group 1. Which statement correctly explains why they have similar, but not identical, reactions?
The table below shows properties of four elements. Which element is most likely a metal? [table] Element / Electrical Conductivity / Oxide Character ; W / Good conductor / Basic ; X / Poor conductor / Acidic ; Y / Poor conductor / Basic ; Z / Good conductor / Acidic