The diagram represents a convection current in the Earth's mantle. Descriptions of the events at each of the positions are shown. Move each number from the diagram to the blank box that describes the event
occurring at the position in the convection current.
Convection Current in Mantle
crust
3
Descriptions
Movement of loss dense
material
Heating of cooler
matorial
Cooling of warmer
material
Movement of densor
material
no

There are main groups in the modern periodic table of elements

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.

If oil spills continue, all of the following should be expected except (2 points) death of aquatic life. polluted groundwater. decreased soil productivity. increased global temperatures.