Question

1. as you move across a period of the periodic table from left to right, the atomic radii of the elements _______

a) increase.

b) decrease.

c) remain constant.

d) show no pattern.

Explanation:

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<reasoning>

Analyze the effect of moving left to right across a period

\[
\text{Protons } (Z) \uparrow \implies \text{Effective Nuclear Charge } (Z_{\text{eff}}) \uparrow
\]

Determine the effect on atomic radius

\[
\text{Electrostatic Attraction} \uparrow \implies \text{Electron Cloud Pull} \implies \text{Atomic Radius} \downarrow
\]
</reasoning>

<answer>
<mcq-option>A) increase.</mcq-option>
<mcq-correct>B) decrease.</mcq-correct>
<mcq-option>C) remain constant.</mcq-option>
<mcq-option>D) show no pattern.</mcq-option>
</answer>

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Answer:

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<reasoning>

Analyze the effect of moving left to right across a period

\[
\text{Protons } (Z) \uparrow \implies \text{Effective Nuclear Charge } (Z_{\text{eff}}) \uparrow
\]

Determine the effect on atomic radius

\[
\text{Electrostatic Attraction} \uparrow \implies \text{Electron Cloud Pull} \implies \text{Atomic Radius} \downarrow
\]
</reasoning>

<answer>
<mcq-option>A) increase.</mcq-option>
<mcq-correct>B) decrease.</mcq-correct>
<mcq-option>C) remain constant.</mcq-option>
<mcq-option>D) show no pattern.</mcq-option>
</answer>

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