4. In which of these graphs are both runners moving at the same speed? 40
40
A
B.
30
30
Distance from starting line (metes)
Distance from starting line (metes)
20
20
10
10
0
0
1
2
1
2
Time (seconds)
3
Time (seconds)
40
40
C
D
30
30
Distance from starting line (meters)
Distance from starting line (metes)
20
200
10
10
0
1
2
3
Time (seconds)
1
3
Time (seconds
O A. graph A.
B. graph B
C. graph C
O D. graph D
I’m pp

What is the composition, in atom percent, of an alloy that consists of 4.5 wt% pb and 95.5 wt% sn? the atomic weights for pb and sn are 207.19 g/mol and 118.71 g/mol, respectively.(a) 2.6 at% pb and 97.4 at% sn(b) 7.6 at% pb and 92.4 at% sn(c)97.4 at% pb and 2.6 at% sn(d) 92.4 at% pb and 7.6 at% sn

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.

According to the vsepr theory what is the shape of a molecule that has a central atom valence three other items with no lone pairs of electrons