Metallic Bonds

Which statement best compares the melting points of magnesium and sodium?

• Magnesium has a higher melting point because it contributes one additional electron per atom than sodium in the electron sea.

• Magnesium has a higher melting point because it contributes two additional electrons per atom than sodium in the electron sea.

• Sodium has a higher melting point because it contributes one fewer electron per atom than magnesium in the electron sea.

• Sodium has a higher melting point because it contributes two fewer electrons per atom than magnesium in the electron sea.

Answer explanation

Magnesium has a higher melting point because it contributes two electrons per atom rather than one into the electron sea, leading to stronger metallic bonding.

Tags

112.43.c.1.G

112.43.c.3.A

A model of metallic bonding is shown below. This model can help us describe metallic bonding in terms of —

• Delocalized electrons

• Crystal lattices

• Ionic bonds

• Electron transfer

Answer explanation

Metallic bonding involves delocalized electrons that move freely throughout the metal lattice, allowing for conductivity and malleability. This is distinct from ionic bonds and electron transfer, making 'delocalized electrons' the correct choice.

Tags

112.43.c.1.G

112.43.c.3.A

Scientists at a metallurgic factory are testing different metals to study the strength of the electrical forces between their atoms. They determined the force needed to bend a sheet of each metal and found that metal A requires 50 N of force, metal B requires 30 N, metal C requires 70 N, and metal D requires 100 N. Metal (a)   is likely to have the lowest melting point, because it is the most (b)   metal. Which terms best complete the sentence?

• ductile

• A

• C

• D

• B

• malleable

Answer explanation

Metal B requires the least force (30 N) to bend, indicating it is the most malleable. Malleability is the ability to deform under stress, often correlating with lower melting points.

Tags

112.43.c.1.G

112.43.c.3.A

The image shows a diagram for a suspension bridge such as the Golden Gate.
There are metal elements in the suspenders, towers, cables, and especially the deck. The engineers who design bridges need to consider the properties of metals such as ductility and malleability.

If a strong force acts on the metal towers of the suspension bridge, the tower will not break into pieces like glass, but will bend instead. Which property of metals explains this phenomenon?

• Brittleness

• Conductivity

• Ductility

• Malleability

Answer explanation

The property that explains why the metal towers bend instead of breaking is malleability. Malleable materials can deform under stress without fracturing, allowing the towers to withstand strong forces.

Tags

112.43.c.1.G

112.43.c.3.A

What property of metals is being shown in figure 1(b) in the image?

• malleable (bend without breaking)

• ductile (stretched into a wire)

• conductive (can conduct electricity)

• shiny

Answer explanation

The property shown in figure 1(b) is conductivity, as metals are known for their ability to conduct electricity efficiently. This distinguishes them from other properties like malleability or ductility.

Tags

112.43.c.1.G

112.43.c.3.A

What property of metals is the image describing?

• malleable (bend without breaking)

• ductile (stretched into a wire)

• conductive (can conduct electricity)

• shiny

Answer explanation

The image describes the property of ductility, which allows metals to be stretched into wires without breaking. This is a key characteristic of metals, distinguishing them from other materials.

What property of metals is the image describing?

• malleable (bend without breaking)

• ductile (stretched into a wire)

• conductive (can conduct electricity)

• shiny

Answer explanation

The image describes the property of ductility, which allows metals to be stretched into wires without breaking. This is a key characteristic of metals, distinguishing them from other materials.

Tags

112.43.c.1.G

112.43.c.3.A