1) Which element has the largest first ionization energy? A) Rb, B) Fr, C) K, D) Na, E) Mg
Answer: E
2) Which has the highest electronegativity?
A) Na, B) Cs, C) Si, D) Te, E) Cl
Answer: E
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
Answer: C)
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
Answer: C)
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
Answer: B)
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!
To find the answer to question 1, we need to compare the first ionization energies of the elements listed. The first ionization energy is the amount of energy required to remove one electron from the outermost shell of an atom. The general trend is that ionization energy increases from left to right across a period in the periodic table.
In this case, we have the elements Rb, Fr, K, Na, and Mg. Since these are all in the same period (period 5), we compare their atomic numbers. The larger the atomic number, the greater the ionization energy. Among these elements, Mg has the largest atomic number, which means it has the largest first ionization energy. Therefore, the answer is E) Mg.
To find the answer to question 2, we need to compare the electronegativity values of the elements listed. Electronegativity is a measure of the ability of an atom to attract a shared pair of electrons towards itself in a covalent bond. The general trend is that electronegativity increases from left to right across a period and decreases from top to bottom within a group in the periodic table.
In this case, we have the elements Na, Cs, Si, Te, and Cl. Among these, Cl has the highest electronegativity. Therefore, the answer is E) Cl.
To find the answer to question 3, we need to arrange the given bonds in order of increasing polarity. Polarity refers to the separation of electric charge within a molecule, resulting in a molecule having a positive and negative end.
Considering the given options, H-F, F-F, O-F, and arranging them in order of increasing polarity, we find that the correct arrangement is C) F-F, H-F, O-F. This is because the fluorine atom is highly electronegative and results in a polar bond with hydrogen and oxygen.
To find the answer to question 4, we need to determine which of the given compounds contain at least one polar covalent bond. A polar covalent bond is a type of chemical bond where there is an unequal sharing of electrons between atoms. This occurs when the electronegativity difference between atoms is significant.
Among the given compounds, HCl and CO both contain polar covalent bonds, as there is an electronegativity difference between the hydrogen and chlorine in HCl and the carbon and oxygen in CO. Therefore, the answer is C) 2.
To find the answer to question 5, we need to identify the property that decreases as we move from left to right across the periodic table. The properties listed are ionization energy, atomic radii, number of valence electrons, electronegativity.
Among these properties, the atomic radii decreases as we move from left to right across a period in the periodic table. Therefore, the answer is B) Atomic radii.