| 1 | An acid can react with a base to form a salt. | |
| 2 | But low-expansion glass is much costlier than soda-lime glass. | |
| 3 | It is a curare alkaloid derived from the South American plant. | |
| 4 | It is possible that Kr and Ar could also act as Lewis bases, but evidently they cannot compete with HF. | |
| 5 | Conventional soda-lime glass expands too much, so welding introduces stresses that can lead to failure. |