1 The diagram below shows two continents where Mesosaurus fossils have been found. Mesosaurus was a freshwater reptile that existed on Earth about 250 million years ago.
Atlantic
Ocean
Africa
South
America
Mesosaurus
(Not drawn to scale )
Which statement best explains why these freshwater Mesosaurus fossils are found
today in rock layers in both South America and Africa?
A Mesosaurus swam across the ocean between the continents.
B The continents were once connected as a single landmass.
C Global warming has been rising the sea level in the Atlantic Ocean.
D The remains of Mesosaurus were carried across the ocean by predators

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.

The atom fluorine generally will become stable through the formation of an ionic chemical compound by accepting electron(s) from another atom. this process will fill its outer energy level of electrons.

Δu of , in kj/kg, as it isto k, (a)as a of , (b) at , (c) at .