Metro Education

28/05/2026

If 4 moles of Na react completely according to the equation below, how many moles of Cl2 gas are required?

A. 1 mol
B. 2 mol
C. 4 mol
D. 8 mol

28/05/2026

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28/05/2026

What is the molar mass of NaOH?

A. 23 g/mol
B. 40 g/mol
C. 56 g/mol
D. 58.5 g/mol

28/05/2026

How many moles of water are produced from 3 moles of oxygen in the equation below?

A. 2 mol
B. 3 mol
C. 4 mol
D. 6 mol

28/05/2026

Which of the following trends is correct for Group 1 elements with respect to ionization energy?

A. Li < Na < K
B. Li > Na > K
C. Li = Na = K
D. K > Li > Na

27/05/2026

Which element has a more stable half-filled p-subshell?

A. Oxygen
B. Nitrogen
C. Fluorine
D. Neon

27/05/2026

Which sequence is arranged in increasing ionization energy?

A. Na < Mg < Al
B. K < Na < Li
C. F < O < N
D. Ar < Cl < S

27/05/2026

Ionization energy generally increases across a period because:

A. Atomic radius increases
B. Shielding effect increases greatly
C. Nuclear charge increases
D. Electrons are removed more easily

27/05/2026

Ionization energy is the minimum amount of energy required to remove the most loosely bound electron from an isolated gaseous atom.
General Trend in the Periodic Table
Across a Period (Left → Right)
Ionization energy generally increases across a period.
Reason:
Nuclear charge increases.
Atomic radius decreases.
Electrons are held more strongly by the nucleus.
Example in Period 3:
Na < Mg < Al < Si < P < S < Cl < Ar

Down a Group (Top → Bottom)
Ionization energy generally decreases down a group.
Reason:
Atomic size increases.
More electron shells cause shielding.
Outer electrons are farther from the nucleus.
Example in Group 1:
Li > Na > K > Rb > Cs

Between k and cl which element has the higher ionization energy.

27/05/2026