Nanoparticles: GCSE Combined Science Chemistry practice questions

Answer: 5 × 10⁻⁸ m

1. 1 nm = 1 × 10⁻⁹ m.
2. 50 × 10⁻⁹ = 5 × 10⁻⁸ m.

Answer: 100

1. Divide the larger diameter by the smaller.
2. 5000 ÷ 50 = 100.

Answer: 0.6

1. Surface area = 6 × 100 = 600 cm².
2. Volume = 1000 cm³.
3. 600 ÷ 1000 = 0.60.

Answer: 300 nm

1. To change metres into nanometres, multiply by 10⁹.
2. 3 × 10⁻⁷ × 10⁹ = 300 nm.

Answer: 12

1. Surface area = 6 × 0.25 = 1.5 cm².
2. Volume = 0.125 cm³.
3. 1.5 ÷ 0.125 = 12.

Answer: they may enter the body and cause harm

1. Nanoparticles are very small.
2. They may enter cells and cause harm, but the effects are not fully known.

Answer: they block ultraviolet light and are transparent on the skin

1. They are small, so the cream is clear.
2. They have a large surface area and block ultraviolet light well.

Answer: a larger proportion of its atoms are on the surface

1. More of the atoms are on the surface.
2. A bigger fraction of atoms can react or interact.

1 × 10⁻⁹ m.

1 nm to 100 nm.

100 nm to 2500 nm.

2500 nm to 10 000 nm.

6 × L².

L³.

6 ÷ L.

It increases.

They have a large surface area, so less material is needed.

Titanium dioxide and zinc oxide.

They kill bacteria.

They may enter cells and the long-term effects are unknown.

A few hundred.

Multiply by 10⁻⁹.

A much larger share of its atoms are on the surface.

The total area of the outside of an object.

The amount of space inside an object.

Six.

3.

It doubles.

Dust.

Multiply by 10⁹.

It has a larger surface area to volume ratio, so more sugar touches the water.