smc-4264-50-Patterns in Metal Activity

CHEMISTRY, M3 EQ-Bank 13

Explain how the trends in ionisation energy, atomic radius, and electronegativity across a period affect the reactivity of metals. (3 marks)

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→ As you move across a period from left to right, the atomic radius decreases due to the increasing nuclear charge, which pulls the electrons closer to the nucleus.

→ This leads to an increase in ionisation energy, making it harder to remove an electron from a metal atom.

→ Additionally, electronegativity increases across the period, meaning that metals are less likely to lose electrons.

→ As a result, the reactivity of metals decreases across a period because it becomes more difficult for them to lose electrons and participate in chemical reactions.

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→ As you move across a period from left to right, the atomic radius decreases due to the increasing nuclear charge, which pulls the electrons closer to the nucleus.

→ This leads to an increase in ionisation energy, making it harder to remove an electron from a metal atom.

→ Additionally, electronegativity increases across the period, meaning that metals are less likely to lose electrons.

→ As a result, the reactivity of metals decreases across a period because it becomes more difficult for them to lose electrons and participate in chemical reactions.

CHEMISTRY, M3 EQ-Bank 11 MC

Which of the following trends explains why metals become more reactive as you move down a group in the periodic table?

Increasing ionisation energy
Increasing electronegativity
Decreasing atomic radius
Decreasing ionisation energy

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\(D\)

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→ As you move down a group in the periodic table, metals become more reactive because the ionisation energy decreases.

→ This means it requires less energy to remove the outermost electron.

→ Lower ionisation energy is directly related to higher reactivity because metals more readily lose electrons in reactions, making them more reactive.

\(\Rightarrow D\)

CHEMISTRY, M3 EQ-Bank 7

Complete the table below, describing the reactivity characteristics of the three metals listed. (3 marks)

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\begin{array} {|l|l|l|l|}
\hline
\ \ \ \ \textbf{Metal} \ & \ \ \ \ \textbf{Reactivity with} \ \ \ \ &\ \ \ \ \textbf{Reactivity with}\ \ \ \ & \ \ \ \ \textbf{Reactivity with}\ \ \ \ \ \ \\ & \ \ \ \ \ \ \ \ \ \ \ \textbf{water} & \ \ \ \ \ \ \ \ \textbf{dilute acid} & \ \ \ \ \ \ \ \ \textbf{oxygen}\\
\hline
& \text{Violent reaction that} & \text{Highly exothermic,} & \text{Burns rapidly to form} \\ \text{Potassium (K)} & \text{ignites hydrogen gas} & \text{ignition of the hydrogen} & \text{oxide which combusts}\\ & \text{produced.} & \text{produced.} & \text{spontaneously in air.} \\
\hline
& \text{Reacts slower with no} & \text{Bubbles slowly to} & \text{Burns when heated with} \\ \text{Zinc (Zn)} & \text{combustion (can be sped} & \text{moderately with no} & \text{oxygen, forming a less} \\ & \text{up using steam).} & \text{ignition.} & \text{reactive oxide layer (may}\\ & & & \text{further react with water).} \\
\hline
& & & \text{Slowly reacts, producing} \\ \text{Copper (Cu)} & \text{No reaction.} & \text{No reaction.} & \text{highly stable oxide layer} \\ & & & \text{that prevents further} \\ & & & \text{oxidation.} \\
\hline
\end{array}

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CHEMISTRY, M3 EQ-Bank 6

Metals such as Lead, Copper, Mercury and Silver do not react with dilute acids but will react with the same acids at higher concentration levels.

Explain why this occurs with reference to first ionisation energy. (3 marks)

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→ First ionsiation energy refers to the energy required to remove a valence electron from a metal.

→ Metals react in their ionised state and the less energy that is required to reach this state, the more reactive the metal.

→ Lead, Copper, Mercury and Silver require more energy to remove their outer valence electrons and consequently are only reactive in the presence of stronger oxidising agents.

→ Concentrated acids have more oxidising ability than their dilute counterparts and can react with these metals.

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→ First ionsiation energy refers to the energy required to remove a valence electron from a metal.

→ Metals react in their ionised state and the less energy that is required to reach this state, the more reactive the metal.

→ Lead, Copper, Mercury and Silver require more energy to remove their outer valence electrons and consequently are only reactive in the presence of stronger oxidising agents.

→ Concentrated acids have more oxidising ability than their dilute counterparts and can react with these metals.