週期表：练习题

In the periodic table, the elements are arranged in columns known as groups. Which statement correctly identifies a trend in properties for Group 1 elements (alkali metals) compared to Group 7 elements (halogens)?

Compared to the alkali metals in Group 1, which of the following is a characteristic property of transition metals?

Fluorine is more reactive than Chlorine. Which of the following provides the most accurate explanation for this difference in reactivity within Group 7?

In Group 1 of the periodic table, the reactivity of the alkali metals increases as the atomic number increases. Which statement correctly explains this trend?

Which of the following statements accurately compares the chemical reactivity of Transition Metals and Group 1 Metals?

Explain why the elements in Group 0 (the noble gases) are generally unreactive in terms of their electronic structure.

State two physical properties of transition metals that are significantly different from the properties of Group 1 alkali metals.

Explain why Mendeleev left gaps in his version of the periodic table and how his predictions were later validated.

Elements in the periodic table are arranged in order of their atomic number. Elements in the same group often show similar chemical properties and trends in their physical properties.

(a) Explain why elements in Group 7 (the halogens) have similar chemical properties. (1 point)

(b) The reactivity of the halogens changes as you move down the group. Describe the trend in reactivity from fluorine to iodine and explain this trend in terms of electronic structure. (3 points)

(c) A student adds chlorine water to a solution of potassium bromide. Describe what the student would observe and write a balanced symbol equation for the reaction. (2 points)

Elements in the periodic table are arranged in a specific way that reflects their atomic structure and determines their chemical behavior.

(a) State the property used to arrange elements in the modern periodic table and explain why Mendeleev's decision to leave gaps in his earlier table was crucial for its eventual acceptance.

(b) Explain the trend in reactivity as you go down Group 7 (the halogens) from fluorine to iodine. Your answer should refer to the atomic structure and the energy levels of the outer electrons.

(c) Chlorine reacts with potassium bromide solution in a displacement reaction. Write the balanced symbol equation for this reaction and explain, in terms of electrons, why this is classified as a redox reaction.