Chemistry - check answers
posted by Amanda .
1) Which element has the largest first ionization energy? A) Rb, B) Fr, C) K, D) Na, E) Mg
2) Which has the highest electronegativity?
A) Na, B) Cs, C) Si, D) Te, E) Cl
3) In which of the following are the bonds arranged in order of increasing polarity? A) H-F, O-F, F-F, B) H-F, F-F, O-F, C) F-F, H-F, O-F, D) F-F, O-F, H-F, E) O-F, F-F, H-F
4) How many of the following contain at least one polar covalent bond? KNO3, HCl, F2, CO. A) 0, B) 1, C) 2, D) 3, E) 4
5) Which of the following properties decreases as we move from left to right across the periodic table? A) Ionization energy, B) Atomic radii, C) # of valence electrons, D) Electronegativity, E) Two of the above
All of these look ok except 3. C is not right for 3. Look up the electronegativity of each element and subtract to find the relative polarity of each compound.
Would D) be correct for 3?
Yes, but you show know this is correct from
F-F = 4.0-4.0 = 0
O-F = 4.0-3.5 = 0.5
H-F = 4.0-2.1 = 1.9
F-F is least polar
H-F is most polar.
Got it. Thanks a lot!