Year 9 Science · Unit 2 · Lesson 10

Metallic Bonding and Bond Types

Foundation Worksheet

Name
Date
Class

Learning Goals

Warm Up

Fill the gap

Choose the correct word from the word bank. Each word is used once. Two words will not be used.

lustre lattice ductile shared malleable voltage transferred cations sea delocalised

In a metal, the atoms release their valence electrons and form a regular of positive metal . The released electrons are not attached to any one atom. They form a of electrons that moves freely through the whole metal. When a is applied, these free electrons drift and carry charge, so metals conduct electricity. Metals are (they can be hammered into sheets) and (they can be drawn into wire), because layers of ions can slide without breaking the bond. Polished metals have a shiny .

True or false? Fix the false ones

Circle T or F. If a statement is false, correct it on the line.

Metals conduct electricity because they have free electrons that can move through the structure.

Correct it:

T
F

Metallic bonding means atoms sharing electrons in pairs, like covalent bonds.

Correct it:

T
F

When a metal wire conducts, its positive ions move towards the negative terminal.

Correct it:

T
F

Copper can be drawn into wire because the electron sea lets layers of ions slide without breaking the bond.

Correct it:

T
F

Metallic bonding only happens in pure metals, not in alloys.

Correct it:

T
F

1. Name the two types of particle in a metal, and describe the attraction that holds them together.

Recall 2 marks

Your Turn

Sort it: ionic, covalent or metallic?

Write each item in the correct box. Four items go in each box.

NaCl shares pairs of electrons Cu brittle when hit malleable H₂O conducts as a solid electrons transferred made of separate molecules delocalised electrons conducts only when melted or dissolved low melting point

Ionic

Covalent (simple molecules)

Metallic

Go Deeper

Scenario: metals that melt in your hand

Metals are often described as having high melting points. A science show hands the audience a spoon made of gallium, which melts if you hold it for a while. Table 1 shows why not every metal is hard to melt.

Table 1. Melting points of six metals
MetalCopperMercuryAluminiumGalliumIronTin
Melting point (°C)1085−39660301538232

Source: data book values, rounded to the nearest degree.

2. Which metal is a liquid at room temperature (25 °C)? Which one melts in your hand (about 35 °C)? A frying pan can reach 250 °C. Which metals in the table would melt in it?

Apply 3 marks

3. Does Table 1 support the statement “all metals have high melting points”? Use two values from the table in your answer.

Analyse 2 marks

Show What You Know

4. House wiring is copper wire covered in PVC plastic. PVC is made of large covalent molecules. Explain why copper is chosen to carry the current, why it can be bent into place, and why the PVC coating keeps people safe.

Analyse 4 marks

HSCScience · Year 9 Science · Unit 2 · Lesson 10 · Foundation Worksheet