Educational worksheet on atoms and the periodic table, featuring matching, fill-in-the-blank, and vocabulary exercises.

Here's the complete solution to all three sections of the worksheet, with clear explanations.

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## Section 1: Match the family with its most important characteristics

| Number | Family | Letter | Characteristic | Explanation |
|--------|----------------------|--------|-------------------------------------------------|-------------|
| 1 | Alkali metal | D | Most reactive metal | Group 1 metals (e.g., Na, K) are extremely reactive, especially with water. They lose one electron easily to form +1 ions. |
| 2 | Alkaline earth metal | E | 2nd most reactive metal | Group 2 metals (e.g., Mg, Ca) are very reactive but less so than alkali metals. They form +2 ions. |
| 3 | Transition metals | B | Common metal, high melting point | These include iron, copper, zinc — widely used in industry due to strength and high melting points. |
| 4 | Halogen family | A | Most reactive nonmetal | Group 17 elements (e.g., F, Cl) are highly reactive nonmetals that gain one electron to form -1 ions. Fluorine is the most reactive element overall. |
| 5 | Noble gases | C | Do not react | Group 18 elements (e.g., He, Ne, Ar) have full valence shells → very stable and chemically inert. |

✔ Correct Matches:
- 1 → D
- 2 → E
- 3 → B
- 4 → A
- 5 → C

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## Section 2: Fill in the chart — Particle, Charge, Location

Use the word bank: *negative, neutral, positive, inside nucleus, outside nucleus*

| Particle | Charge | Location |
|-----------|------------|------------------|
| Proton | positive | inside nucleus |
| Electron | negative | outside nucleus |
| Neutron | neutral | inside nucleus |

🔬 Explanation:

- Protons are positively charged particles found in the nucleus.
- Electrons are negatively charged particles orbiting the nucleus (outside).
- Neutrons have no charge (neutral) and are also located in the nucleus.

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## Section 3: Fill in the blanks using the word bank

Word bank: *broken, stretched, hammered, wires, sheets, electricity, heat, reflects, shiny*

a) Malleable – A substance can be hammered into sheets
→ Malleability means a material can be shaped by hammering or rolling without breaking (e.g., gold foil).

b) Ductile – A substance can be stretched into wires
→ Ductility means a material can be drawn into thin wires (e.g., copper wires).

c) Luster – How light reflects off a substance; how shiny it is.
→ Luster describes how a surface reflects light — metallic luster = shiny.

d) Brittle – Easily broken into pieces.
→ Brittle materials shatter when struck (e.g., glass, chalk).

e) Conductor – A substance that can carry electricity or heat.
→ Metals conduct both heat and electricity well due to free-moving electrons.

✔ Final Answers:

a) hammered, sheets
b) stretched, wires
c) reflects, shiny
d) broken
e) electricity, heat

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## ✔ Summary of All Answers:

Section 1:

1-D, 2-E, 3-B, 4-A, 5-C

Section 2:

- Proton: positive, inside nucleus
- Electron: negative, outside nucleus
- Neutron: neutral, inside nucleus

Section 3:

a) hammered, sheets
b) stretched, wires
c) reflects, shiny
d) broken
e) electricity, heat

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