The mass of an atom of beryllium is 1.5 x 10^-26 kg. How many beryllium atoms are present in beryllium film of mass 0.37 g used as a window on an x-ray tube? Answer in units of atoms.

There are 2.5 * 10^22 beryllium atoms in 0.37 grams

Explanation:

Step 1: Data given

The mass of an atom of beryllium is 1.5 x 10^-26 kg.

Total mass = 0.37 grams

Step 2: Calculate number of atoms

1 atom = 1.5 * 10 ^-26 kg

X atoms = 0.00037 kg

X = 0.00037/1.5*10^-26

X = 2.467 * 10^22 atoms ≈ 2.5 * 10^22 atoms

There are 2.5 * 10^22 beryllium atoms in 0.37 grams