The average width of a plant vacuole observed under a microscope is 0.045 mm.
Which of the following is this width expressed in micrometres (μm\mu\text{m}μm)?
0.45 μm0.45\text{ }\mu\text{m}0.45 μm
45 μm45\text{ }\mu\text{m}45 μm
450 μm450\text{ }\mu\text{m}450 μm
45 000 μm45\,000\text{ }\mu\text{m}45000 μm
