What solid elements have a low electronegativity???

The electron pairs shared between two atoms are not necessarily shared equally. For example, while the shared electron pairs is shared equally in the covalent bond in Cl2, in NaCl the 3s electron is stripped from the Na atom and is incorporated into the electronic structure of the Cl atom - and the compound is most accurately described as consisting of individual Na+ and Cl− ions (ionic bonding). For most covalent substances, their bond character falls between these two extremes. We demonstrated below, the bond polarity is a useful concept for describing the sharing of electrons between atoms within a covalent bond:

Explanation:

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.