1. Oxygen (O): Makes up about 46.6% of the Earth's crust.
2. Silicon (Si): Makes up about 27.7% of the Earth's crust.
3. Aluminum (Al): Makes up about 8.1% of the Earth's crust.
4. Iron (Fe): Makes up about 5.0% of the Earth's crust.
5. Calcium (Ca): Makes up about 3.6% of the Earth's crust.
6. Sodium (Na): Makes up about 2.8% of the Earth's crust.
7. Potassium (K): Makes up about 2.6% of the Earth's crust.
8. Magnesium (Mg): Makes up about 2.1% of the Earth's crust.
These eight elements make up over 99% of the Earth's crust.
It's important to note that these percentages are based on weight. If we look at the *number of atoms* present, the ranking changes slightly, with silicon being the most abundant element by atom count.
