Answer:
Climate change and an increase in unpredictable and extreme weather is a growing challenge. Long periods of drought affect clean water supplies while flooding can pollute clean water sources and cause outbreaks of disease.
Thus BeF2 is of most covalent character.
Anyways, covalent/ionic character is a bit tricky to figure out; we measure the difference in electronegativity of two elements bonding together and we use the following rule of thumb: if the charge is 0 (or a little more), the bond is non-polar covalent; if the charge is > 0 but < 2.0 (some references say 1.7), the bond is polar covalent; if the charge is > 2.0 then the bond is ionic. Covalent character refers to smaller electronegativity difference while ionic character refers to greater electronegativity difference.
Now, notice all of our bonds are with F, fluorine, which has the highest electronegativity of 3.98. This means that to determine character we need to consider the electronegativities of the other elements -- whichever has the greatest electronegativity has the least difference and most covalent character.
Na, sodium, has electronegativity of 0.93, so our difference is ~3 -- meaning our bond is ionic. Ca, calcium, has 1.00, leaving our difference to again be ~3 and therefore the bond is ionic. Be, beryllium, has 1.57 yielding a difference of ~2.5, meaning we're still dealing with ionic bond. Cs, cesium, has 0.79, meaning our difference is again ~3 and therefore again our compound is of ionic bond. Lastly, we have Sr, strontium, with an electronegativity of 0.95 and therefore again a difference of roughly 3 and an ionic bond.
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<span>If I done the math correctly it is 3729J because you multiply 16.5 g by the 2260 J/g and get 3729 J</span>
Answer:
The molecular formula of X is C8H9NO2
Explanation:
Step 1: Data given
exact mass of 151.0640
Molar mass of C = 12 g/mol
Molar mass of H = 1.00783 g/mol
Molar mass of O = 15.9949 g/mol
Molar mass of N = 14.0031 g/mol
Step 2: Calculate molar mass of C7H5NO3
7*12 + 5*1.00783 + 14.0031 + 3*15.9949 = 151.02695 g/mol
Step 3: Calculate molar mass of C8H9NO2
8*12 + 9*1.00783 + 14.0031 + 2*15.9949 = 151.06337 g/mol
Step 4: Calculate molar mass of C10H17N
10*12 + 17*1.00783 + 14.0031 = 151.13621 g/mol
The molecular formula of X is C8H9NO2