The organism was once a clam and most likely became a fossil after being buried by silt in its watery environment after death. Might need more clarification on what exact answer you need.
<span>Ca^(2+). Calcium is an alkaline earth metal with an atomic number of 20. Its electronic configuration is (2, 8, 8, 2). From the electronic configuration it would be observed that calcium has two valence electrons. Calcium shares these two electrons with non metals like sulphur in an ionic bond to obtain an outer shell which is full octet. Let me use Sulphur. When calcium gives out its two valence electrons its electronic configuration becomes (2, 8, 8) thereby obtaining a stable out shell and the calcium ion becomes Ca^(2+). The sulphur also obtains a stable octet because it has 6 valence electron initially.</span>
Answer:
[α] = -77.5° / 
Explanation:
Given;
Mass of optically pure substance in the solution = 10 g
Volume of water = 500 mL
Length of the polarimeter, l = 20 cm = 20 × 0.1 dm = 2 dm
measured rotation = - 3.10°
Now,
The specific rotation ( [α] ) is given as:
[α] = 
here,
α is the measured rotation = -3.10°
c is the concentration
or
c = 
or
c = 
or
c = 0.02 g/mL
on substituting the values, we get
[α] = 
or
[α] = -77.5° /
