for each of the following interactions, identify action action and reaction forces (action reaction pairs): a. a hammer hits a nail b. earths gravity pulls down on you c. a helicopter blade pushes air downward d. you step off a curb e. you pat your friend on the back f. a wave hits a rocky shore

Five students had to answer the question how are elements arranged in a periodic tabledamon: i think the elements are arranged by increasing massflo: i think the elements are arranged according to their properties sienna: i think the elements are arranged by when their discovers kyle: i think the elements are arranged according to how common they areglenda: i don't agree with any of themwho is right

An atom of sodium-23 (atomic number = 11) has a positive charge of +1. give this information, how many electrons does it have? how many proteins and neutrons does this atom have

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.