Lesson: Chapter 7 — Quantification of Elements and Compounds

7.1. Relative atomic mass 6 of 12 Reset answers

Clear all your answers?

This erases every answer in this set and starts you again at question one. Your score will be gone.

Type these four numbers to confirm:

Those numbers don't match. Look at them again and type them.

Yes, clear Keep them

Question 6

An atom of an element has a mass of 3.32 × 10^-23 g. The atomic mass unit is 1.66 × 10^-24 g. What is its relative atomic mass?

A 0.05 B 240 C 20 D 1.67

The right answer is the one marked above.

20. A_r = (3.32 × 10^-23 g) ÷ (1.66 × 10^-24 g) = 20.

1.67 comes from dividing by the whole mass of a carbon atom, 1.99 × 10^-23 g, instead of by the atomic mass unit. 0.05 comes from doing the division the wrong way round.

Answer the question to continue.