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Module 3
Question | Answer |
---|---|
What is a period? | A horizontal row of elements in the periodic table. |
What is periodicity? | The trend in properties that is repeated across each period. |
Why does the ionisation energy increase across a period? | Because the number of protons increases, so there is an increase in nuclear charge. Electrons are added to the same shell which pulls the electron shells closer, decreasing atomic radii. Shielding stays the same. |
Why does the ionisation energy decrease down a group? | Because the number of shells increases, so the atomic radii increases. Due to the increased number of shells, the effect of shielding increases. Nuclear charge is outweighed. |
Do melting and boiling point increase or decrease across a period? | Increase |
Which kind of structures have an increased boiling point? | Giant covalent and giant metallic. |
What is the product of reacting a group 2 metal with oxygen? | An ionic oxide, such as CaO, MgO |
What are the products of reacting a group 2 metal with water? | A hydroxide and hydrogen gas. e.g. Ca(OH)2 |
Does reactivity increase or decrease down group 2? | Increase. |
Does ionisation energy increase or decrease down group 2? | Decrease |
What are the products of reacting a group 2 oxide/hydroxide with an acid? | A salt and water |
What is the product of reacting a group 2 oxide (MgO) with water? | A metal hydroxide |
What is the product of reacting a group 2 hydroxide Ca(OH)2 with water? | An alkaline solution |
What are the products formed from the thermal decomposition of a group 2 carbonate? | A metal oxide and carbon dioxide. |
Name a use of Calcium hydroxide. | Neutralises acid soils |