Free Printable Periodic Trends Worksheets - Free Printable

Let's go through the Periodic Trends Worksheet step by step and solve each question with explanations based on periodic trends.

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1. Circle the best answer that has the:

#### a) Smallest electron affinity
Elements: N, P, As, Sb, Bi
- Electron affinity generally increases (becomes more negative) across a period and decreases down a group.
- Nitrogen (N) has very low electron affinity because it has a half-filled p-subshell (stable configuration), so adding an electron is unfavorable.
- So, N has the smallest (least negative) electron affinity.

✔ Answer: N

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#### b) Largest electronegativity
Elements: Ga, Ge, As, Sc
- Electronegativity increases across a period and decreases down a group.
- Among these:
- Ga (Group 13), Ge (14), As (15), Sc (Group 3)
- As is furthest right → highest electronegativity
- Sc is a transition metal and has low electronegativity

✔ Answer: As

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#### c) Largest ionization energy
Elements: O, S, Sc, Te, Po
- Ionization energy increases across a period and decreases down a group.
- Sc is a transition metal in Period 4, but O and S are nonmetals with high IE.
- However, O has higher IE than S (due to smaller size), but Sc has lower IE than O.
- Let’s compare:
- O > S > Se > Te > Po (trend down Group 16)
- But Sc is in Group 3, Period 4 → relatively low IE
- So among all, O has the highest ionization energy in this list.

Wait — actually, Sc is a metal with low IE. The nonmetals have higher IE.
- Oxygen (O) has high IE, but fluorine is even higher — not here.
- Among these: O has the highest IE.

✔ Answer: O

> Note: Oxygen has higher IE than sulfur, tellurium, polonium, and scandium.

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#### d) Lowest ionization energy
Elements: O, S, Se, Te, Po
- Ionization energy decreases down a group.
- All are in Group 16 (chalcogens).
- Po (Polonium) is at the bottom → largest atomic radius, weakest hold on electrons → lowest IE.

✔ Answer: Po

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#### e) Smallest atomic radius
Elements: F, Cl, Br, I, At
- Atomic radius increases down a group.
- F is at the top of Group 17 → smallest radius.

✔ Answer: F

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#### f) Largest atomic radius
Elements: Li, Na, K, Rb, Cs
- All alkali metals (Group 1)
- Radius increases down the group.
- Cs (Cesium) is the bottom one → largest radius.

✔ Answer: Cs

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2. Low ionization energy is a characteristic of a ________

- Low ionization energy means it's easy to remove an electron → typical of metals, especially alkali metals.
- These elements tend to lose electrons easily.

✔ Answer: Metal (or alkali metal)

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3. What does atomic radius measure?

- It measures the distance from the nucleus to the outermost electron shell of an atom.

✔ Answer: The distance from the nucleus to the outer edge of the electron cloud.

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4. Describe the change in the atomic size across a period and down a group.

- Across a period (left to right): Atomic radius decreases due to increasing nuclear charge pulling electrons closer.
- Down a group: Atomic radius increases due to addition of electron shells (principal energy levels).

✔ Answer:
- Across a period: atomic radius decreases
- Down a group: atomic radius increases

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5. Which element has the largest atomic radius?

- From the periodic table, Francium (Fr) has the largest atomic radius (but not listed).
- If we consider common elements, Cesium (Cs) or Rubidium (Rb) are large.
- But since no options are given, assume general knowledge.

✔ Answer: Francium (Fr) – *though often Cs is used as example*

But if only considering elements in worksheet, Cs is the largest.

✔ Answer: Cs (Cesium)

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6. Explain the main difference between metals and nonmetals.

- Metals tend to lose electrons to form cations; they are shiny, malleable, conductive.
- Nonmetals tend to gain electrons to form anions; they are brittle, poor conductors (except graphite).
- Main difference: Electron behavior – metals lose electrons, nonmetals gain them.

✔ Answer: Metals tend to lose electrons and form positive ions; nonmetals tend to gain electrons and form negative ions.

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7. Determine if the listed pairs have similar or different properties.

#### a) Potassium & Rubidium
- Both alkali metals (Group 1) → similar properties

✔ Similar

#### b) Calcium & Barium
- Both alkaline earth metals (Group 2) → similar properties

✔ Similar

#### c) Sodium & Chlorine
- Na: metal, Cl: nonmetal → very different chemical behavior

✔ Different

#### d) Helium & Krypton
- Both noble gases (Group 18) → chemically inert → similar

✔ Similar

#### e) Phosphorus & Oxygen
- P: nonmetal, O: nonmetal, but different groups → different properties

✔ Different

#### f) Lithium & Fluorine
- Li: metal, F: nonmetal → very different

✔ Different

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8. Which element has the largest electronegativity?

- Electronegativity increases across a period and decreases down a group.
- Fluorine (F) is the most electronegative element.

✔ Answer: Fluorine (F)

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9. Which group (name) would have the lowest ionization energies?

- Alkali metals (Group 1) have lowest ionization energies because they have one valence electron and large atomic radius.

✔ Answer: Alkali metals

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10. Which group (name) has the highest ionization energies?

- Noble gases (Group 18) have very high ionization energies because they have stable, full valence shells.

✔ Answer: Noble gases

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✔ Final Answers Summary:

1.
a) N
b) As
c) O
d) Po
e) F
f) Cs

2. Metal

3. The distance from the nucleus to the outermost electron shell.

4.
- Across a period: atomic radius decreases
- Down a group: atomic radius increases

5. Cesium (Cs) or Francium (Fr) (if allowed)

6. Metals lose electrons to form cations; nonmetals gain electrons to form anions.

7.
a) Similar
b) Similar
c) Different
d) Similar
e) Different
f) Different

8. Fluorine (F)

9. Alkali metals

10. Noble gases

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