Across
- 1. This is a matter made up of particles far apart from each other g__
- 4. This colour is made up of all the colours from the spectrum w___
- 5. This travels in straight lines L_____t
- 6. The number of vibrations per second F_________
- 7. This travels in waves S_______
Down
- 2. This is a matter made up of particles tightly packed together S____
- 3. the unit to measure sound D_______s