The Periodic Table：練習題

Consider the elements Phosphorus (atomic number 15) and Sulfur (atomic number 16). Which of the following correctly describes the acid-base character of their oxides and their electrical conductivity?

A mystery element Z is a solid at room temperature. It does not conduct electricity. When burned in oxygen, it produces a gas that dissolves in water to turn universal indicator red. In which position is Z most likely found in the Periodic Table?

An element X forms an oxide with the formula \(X_2O_3\). This oxide reacts with both hydrochloric acid and sodium hydroxide solution. In which part of the Periodic Table is element X most likely to be found?

Which of the following best explains why Helium and Neon are chemically unreactive, whereas Fluorine and Sodium are highly reactive?

Which statement correctly explains why elements in the same Group of the Periodic Table exhibit similar chemical properties?

Deduce the electronic configuration of an element located in Period 3 and Group 5 of the Periodic Table.

Justify why argon is placed in Group 0 (or Group 8) rather than Group 2, despite both helium and alkaline earth metals having 2 electrons in their outermost occupied shell.

Explain why elements in the same group of the Periodic Table exhibit similar chemical properties.

Elements in the Periodic Table are arranged according to their atomic number and electron configuration.

a) Explain, in terms of electronic configuration, why sodium and potassium are placed in Group 1, while neon and argon are placed in Group 0. (2 points)

b) Sodium reacts with water to form an alkaline solution and a gas. Write a balanced chemical equation for this reaction, including state symbols. (2 points)

c) Predict the acid-base character of the oxide formed when sodium reacts with oxygen. Explain how this character can be used to classify sodium as a metal. (1 point)

The Periodic Table organises elements into groups and periods, which allows us to predict their properties and reactivity.

a) Describe the trend in reactivity of Group 1 metals as you move down the group. Explain this trend in terms of atomic structure and electron shielding.

b) Describe the trend in reactivity of Group 7 non-metals (halogens) as you move down the group. Explain this trend in terms of atomic structure and electron attraction.

c) Write a balanced chemical equation, including state symbols, for the reaction between sodium metal and water.