define hypothesis and theory, and differentiate between a hypothesis and a theory. Significant Digits Questions (1) identify the number of...

1.  define hypothesis and theory, and differentiate between a hypothesis and a theory.

 Significant Digits Questions 

 (1) identify the number of significant digits:

1. 7.5
2. 3.40
3. 209
4. 209.10
5. 1.3 x 103 
6. 27.077
7. 270.00
8. 2.7 x 102

(2) What "significant digit" means in scientific measurements.

(3) Why is it important to note the location of the decimal in every number?