True or false: In an ionic bond, the difference in electronegativities between the two bonding atoms is greater than the difference in a covalent bond.

Match the following vocabulary terms to their definitions. 1. amount of energy required to change 1 gram of material from the solid to the liquid state at its melting point 2. a measure of the kinetic energy of the particles of a substance 3. the amount of heat energy required to raise the temperature of 1 gram of liquid water from 14.5°c to 15.5°c 4. amount of energy required to change 1 gram of material from the liquid to the gaseous state at its boiling point 5. the amount of energy required to change 1 gram of a substance 1°c a. temperature b. latent heat of vaporization c. latent heat of fusion d. calorie e. specific heat

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.

The scheme below is from a series of reactions that are part of a synthesis of vitamin a. answer the following questions with reference to this scheme. (i) what is "reagent a"? (ii) draw a step-by-step mechanism which explains the formation of compound c from compound b (iii) which reagents would you use to form compound e from compounds c and d (reagents b and c)? for each reagent suggested above in (ii) explain the role of the reagent in the reaction to (iv) form compound e. you may wish to do this by drawing a mechanism. 1. addition of reagent a но reagent a 2. н,о" thо oh нон-с compound a. compound b. compound c .ch-оh 1. reagent b "сно 2. reagent c сh oh compound e. compound d.