Question : 31.How many valence electrons present in a chloride ion, Cl−? A) : 1318366

31.How many valence electrons are present in a chloride ion, Cl−?

A) 5

B) 7

C) 8

D) 17

E) 18

32.Which statement correctly describes the basis for the octet rule?

A) Atoms strive to attain eight protons in their nucleus to attain the stability of the nearest noble gas.

B) Atoms have a tendency to form eight bonds with other atoms to attain the stability of a noble gas.

C) Atoms will lose, gain, or share eight electrons to become a noble gas.

D) Atoms are most stable with eight electrons in their outermost shell, and the electron configuration of a noble gas.

E) Atoms are most stable when the number of protons they contain is identical to the noble gas closest to them in the periodic table.

33.Which ion is NOT isoelectronic (i.e. has the same electron configuration) with Ar?  The electron configuration of Ar is shown below.

Ar1s22s22p63s23p6

A) Cl−

B) K+

C) Br−

D) Ca2+

E) S2−

34.The ground state electron configuration of a sulfur atom is shown below.  What is the ground state electron configuration of the ion S2−?

S1s22s22p63s23p4

A) 1s22s22p63s03p4

B) 1s22s22p63s23p6

C) 1s22s22p63s23p2

D) 1s22s22p6

E) 1s22s22p63s33p5

35.Atoms with the biggest radii occur in the _______ region of the periodic table.

A) bottom left

B) top right

C) bottom right

D) top left

E) middle

36.Which best explains why an Al3+ ion is smaller than an Al atom?

A) In forming the Al3+ ion, the Al atom loses the electrons in its outermost energy level, causing a decrease in the atomic radius.

B) In forming the Al3+ ion, the Al atom gains three protons and the resulting net positive charge keeps the electrons more strongly attracted to the nucleus, reducing the radius.

C) The Al3+ ion contains more electrons than the Al atom, which results in a greater attraction for the nucleus and a smaller atomic radius.

D) In forming the Al3+ ion, the Al atom adds electrons into a higher energy level, causing a decrease in the atomic radius.

E) There are more protons in an Al3+ ion than there are in an Al atom.

37.Which element is a halogen in period 4?

A) bromine

B) silicon

C) iodine

D) krypton

E) potassium

38.Hydrogen can form two different ions: a hydrogen ion (H+), and a hydride ion (H−).  Which statement concerning these ions is FALSE?

A) The H+ ion is a cation formed by the loss of one electron; this ion has no valence electrons.

B) The H− ion is an anion formed by the gain of one electron; this ion has a full n=1 energy level.

C) The hydrogen ion and the hydride ion are isotopes.

D) The hydrogen ion and the hydride ion have the same number of protons.

E) The hydrogen ion and the hydride ion have different sizes.

39.The element carbon forms the basis of study in Organic Chemistry.  Which statement about the element carbon is FALSE?

A) Carbon is a period 2 element.

B) Carbon is a group 4 element.

C) Carbon is a nonmetal.

D) Carbon atoms have six valence electrons.

E) Carbon atoms have six protons.

40.What does the mass number minus the atomic number represent?

A)number of protons

B)number of electrons

C)number of neutrons

D)number of protons – number of neutrons

E)number of neutrons – number of protons