Question

14
identify which of these points explain why the group 1 metals are highly reactive with water
i. group 1 metals have relatively low ionization energies.
ii. group 1 metals have the highest effective nuclear charge in their periods.
iii. group 1 metals have a high tendency to lose their outer valence shell electron. *
(0.5 points)
ii and iii
i and ii
i, ii and iii
i and iii
15
complete the following sentence.
__________ are elements that show intermediate properties between metals and non-
metals. * (0.5 points)
enter your answer

Explanation:

• Question 14:
• Statement I: Group 1 metals have low ionization energies. Ionization energy is the energy required to remove an electron. Low ionization energy means it is easy for these metals to lose an electron, which is relevant for reactivity with water (where they lose an electron in the reaction).
• Statement II: Group 1 metals have the lowest (not highest) effective nuclear charge in their periods. Effective nuclear charge is the net positive charge experienced by an electron. Since they are on the left of the period, shielding effect is more prominent compared to right - hand side elements in the period, so this statement is wrong.
• Statement III: Group 1 metals have a high tendency to lose their outer valence shell electron (as they have only one valence electron and a low ionization energy), which is crucial for their reactivity (e.g., in the reaction \(2Na + 2H_2O=2NaOH + H_2\uparrow\), sodium loses an electron).
• Question 15:
• By definition, metalloids are elements that show intermediate properties between metals and non - metals. For example, silicon has some metallic properties (like being a semiconductor, which has some electrical conductivity characteristics similar to metals in a limited sense) and non - metallic properties (like forming covalent compounds).

Answer:

• Question 14: I and III
• Question 15: Metalloids