1. Oxygen (O): ~46.6% by weight

2. Silicon (Si): ~27.7% by weight

3. Aluminum (Al): ~8.1% by weight

4. Iron (Fe): ~5.0% by weight

5. Calcium (Ca): ~3.6% by weight

6. Sodium (Na): ~2.8% by weight

7. Potassium (K): ~2.6% by weight

8. Magnesium (Mg): ~2.1% by weight

These eight elements make up over 98% of the Earth's crust by weight.

It's important to note that the crust is only a very thin layer compared to the Earth's total size. The composition of the mantle and core is significantly different.