Across
- 4. even more strongly with water than sodium
- 5. lightest element that exists.
- 6. is soft enough to cut with a knife.
- 7. red spectral lines in its light.
Down
- 1. moves quickly on the surface aproducesuce hydrogen gas
- 2. only tiny amounts exist in Earth’s crust at any time.
- 3. explode if it touches water.