Bulk & Surface Properties of Matter Including Nanoparticles (Edexcel GCSE Chemistry)

Particles are grouped into categories depending on their diameter.

Particle X has a diameter of  2.5 x 10^-7 m.

Which particle is this most likely to be?

This question is about properties of materials.

Figure 6 shows some properties of steel and Kevlar®.

Figure 6

Body armour, such as a bullet-proof vest, could be manufactured using either of these materials.

Explain two reasons why Kevlar® is preferred to steel as the material for body armour.

The use of nanoparticles has increased in recent years.

i) The length of one side of a cube of silver is 2 cm as shown in Figure 7.

Figure 7

   Calculate the surface area to volume ratio of this cube of silver.

(3)

surface area to volume ratio = ..............................................................

ii) Suggest an explanation of why a given mass of silver is more effective as a catalyst when used as nanoparticles rather than in a powder form.

(3)

A nanoparticle of a metal oxide is a cube. 

Each side has a length of 82 nm. 

What is the volume of the nanoparticle? 

Nanoparticles are used in medicine and can be used to deliver drugs to the cells where they are needed.

Some people are concerned about using nanoparticles this way.

What is the main reason for this concern? 

Figure 2 shows information about three different materials, a composite, a glass and a metal.

Figure 2

Explain which material in Figure 2 is the most suitable material to use in electrical circuits.

i) Nanoparticles are very small.

Some nanoparticles have a radius of 17 nm. The radius of a magnesium atom is 0.16 nm.

Approximately how many times larger is the radius of these nanoparticles than the radius of the magnesium atom?

(1)

ii) A catalyst contains cube‐shaped nanoparticles. Figure 3 shows a diagram of a cube‐shaped nanoparticle. The length of each side of the cube is 9nm.

Figure 3

Calculate the surface area of the cube, in nm².

(2)

surface area = .............................. nm²

iii) Nanoparticles have many uses. Some scientists are concerned about the possible risks of using nanoparticles.

Give one possible risk of using nanoparticles.

(1)

The properties and uses of some materials are given below.

Which does NOT show the correct property or use of the material?

Figure 1 shows a list of particles.

Figure 1

In the spaces below, write the names of these particles in order of increasing particle size.

smallest particle ..........................................

..........................................

..........................................

largest particle ..........................................

Explain a possible risk associated with nanoparticulate materials.

Explain the advantage of using catalysts made of nanoparticles rather than larger particles.

A gold nanoparticle is a cube with sides of 2nm. 

What is the simplest surface area to volume ratio of the nanoparticle?     

i) Titanium(IV) oxide is an ionic solid.
Many ionic solids are soluble in water.

Titanium(IV) oxide is not soluble in water.
Its other physical properties are typical of ionic solids.

Predict one other physical property of titanium(IV) oxide that would be typical of ionic solids.

(1)

ii) The formula of titanium(IV) oxide is TiO₂. Deduce the charge of the titanium ion in titanium(IV) oxide.

(1)

Nanoparticles are very small particles that have unusual properties.

i) Particles less than 100 nanometres in size are classified as nanoparticles. 100 nanometres is

(1)

ii) Nanoparticles of titanium(IV) oxide are used in some sunscreens. Describe a reason why nanoparticles of titanium(IV) oxide are used in some sunscreens.

(2)

iii) Some people are concerned that there is a risk when sunscreens containing nanoparticles are used. Explain a possible risk associated with using nanoparticles in sunscreens.

(2)

This question is about materials and their properties.

FIgure 1 shows a tennis racket.

Table 1 shows the properties of some materials that could be used to make tennis racket frames. 

Table 1

Compare and evaluate the use of the materials to make tennis racket frames.

Heat sinks are objects that absorb and dissipate heat from another object using thermal contact. Figure 2 shows the application of heat sinks in computers, where they are used to protect the processor from being damaged due to overheating.

Thermal grease containing nanoparticles of silver can be applied to the gap between the heat sink and the processor.

Table 2 shows the approximate diameters of different types of particle.

Table 2

i) Calculate how many times smaller the diameter of the nanoparticle is compared to the diameter of the coarse particle.

Give your answer to the appropriate number of significant figures.

(2)

ii) State one advantage of using silver nanoparticles in this application of thermal grease.

(1)

Silver nanoparticles are also known for their antibacterial, antifungal and antiviral properties.

The graph in Figure 3 shows how the size of the nanoparticles affects the mortality rates of different bacteria.

 Two students, A and B, make the following statements based on the graph:

• Student A states that the percentage of bacteria killed decreases as the size of the nanoparticles increases and no further experiments are needed.

• Student B states that the percentage of bacteria killed decreases as the size of the nanoparticles increases but further experiments are needed.

Justify each student's statement. 

Another application of nanoparticles is the use of titanium dioxide and zinc oxide nanoparticles in suncreams.

State one advantage and one disadvantage of using nanoparticles in suncreams.

This question is about nanoparticles and their uses.

Nanoparticles of platinum can be used in modern catalytic converters. 

Catalytic converters are found in car engines and prevent harmful substances that are produced when petrol burns from being released into the air. 

Figure 1 represents a platinum nanoparticle. 

All sides are the same length.

Figure 1

Calculate the surface area to volume ratio of this particle. 

Give your answer in the simplest whole number ratio.

Burning petrol in a car is an exothermic reaction.

Draw and label the reaction profile for an exothermic reaction in Figure 2.

Include labels for:

• Overall energy change

• Activation without a catalyst

• Activation energy with platinum catalyst 

Figure 2

Platinum is a transition metal. 

Describe the bonding and structure of platinum. 

Explain why it is cheaper to use nanoparticles of platinum as opposed to coarse particles of platinum? 

Nanoparticles are used in medicine, and can be used to deliver drugs to the cells where they are needed.

Some people are concerned about using nanoparticles this way.

What is the main reason for this concern? 

Figure 1 shows the surface area to volume ratio for different diameters of spherical nanoparticles. 

Figure 1

What are the correct surface area: volume ratios for spherical nanoparticles with diameters of 80 nm, 100 nm, and 110 nm?

A different nanoparticle is cube shaped, as shown in Figure 2.

The length of one side of this cube is 60 nm.

Figure 2

Show that the surface area : volume ratio for this cube is 1:10.