A protein molecule's diameter is measured as 42 Å using X-ray diffraction. If another measurement instrument gives the diameter in picometers (pm), and the ratio of the two measurements is $\frac{x}{10}$, what is the value of $x$?

The density of a substance is 2 g/cm³. What is its density in kg/m³?

The Planck constant is $6.626 imes 10^{-34}$ J s. Express this in units of eV s (electron-volt seconds), given 1 eV = $1.602 imes 10^{-19}$ J.

The speed of light is approximately $3 imes 10^8$ m/s. If a star is 4 light-years away, what is its distance in kilometers? (1 light-year = distance light travels in one year)

The wavelength of a light wave is 500 nm. Express this wavelength in meters.

Convert 5000 mL to liters.

How many cubic centimeters ($cm^3$) are there in 1 liter?

100 cm is equivalent to how many kilometers?

The pressure of a gas is 760 mmHg. What is this pressure in Pascals? (Given 1 atm = 760 mmHg = $1.013 imes 10^5$ Pa)

How many milligrams are there in 2 grams?

The ratio of SI. Unit of the CGS unit of Planck’s constant is