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8. The atomic mass of an element is 32.07 u and its atomic number is 16. The number of protons contained in the nucleus of an atom of this element is (A) 16 (B) 31 (C) 32 (D) 48
A) 16 atomic # = protons
4. Which hydrated metal ion is most acidic under conditions of equal molar concentration in water? (A) Al3+ (B) Ba2+ (C) K+ (D) Zn2+ (E) Ag+
A) Al3+ has highest charge so it will be most acidic
6. In what respect does an atom of magnesium differ from a magnesium ion (Mg2+)? (A)The ion has a more stable electronic arrangement than the atom. (B)The positive charge on the nucleus of the ion is two units greater than the nuclear charge on the atom. (C)The ion has two more protons than the atom. (D)The ion will react more readily with free Cl2. (E)The ion has two more planetary electrons than the atom.
A) Mg2+ is more stable because it got rid of electrons and is at a complete valence shell
9. The atomic mass of an element is 32.07 u and its atomic number is 16. The element forms a simple ion. The ion will most likely have a charge of (A) 1- (B) 2- (C) 3+ (D) 1+
B) -2 because its same column as oxygen to reach complete valence need 2 more electrons
3. All are potential Lewis bases except (A) NH3 (B) H2O (C) CH4 (D) CN-
C) CH4 is complete and doesn't want to donate anything
2. According to the Lewis definition, an acid is a species (A) having a hydrogen ion. (B) donating a pair of electrons. (C) accepting a pair of electrons. (D) accepting a hydrogen ion.
C) lewis acid accepts a pair of electrons lewis bases donate a pair of electrons
7. A certain atom has the symbol 148 73Px. What does this symbol tell about an atom of the element? (A) It has 148 electrons. (B) It has a valence of 4. (C) It has 221 protons in the nucleus. (D) It has 75 neutrons in the nucleus. (E) Its atomic mass is 73 u.
D) 75 neutrons because mass-atomic number
1. All are examples of Lewis acid-base reactions except (A) Cu2+(aq) + 4NH3(aq) →← [Cu(NH3)4]2+(aq) (B) HCl(g) + NH3(g) → NH4Cl(s) (C) H+(aq) + OH-(aq) →← H2O(l) (D) 2Na(s) + Cl2(g) → 2NaCl(s)
D) NaCl is not a lewis acid-base reaction because there aren't acids or bases in it
5. Which element in Group 5A forms the most basic oxide? (A) N (B) P (C) As (D) Sb (E) Bi
E) Bi forms the most basic oxide (bonding with oxygen) because it is furthest down the periodic table
