Deck 21: Periodic Trends and the S-Block Elements

Question 1

Boron is chemically most similar to _____.

A) silicon
B) carbon
C) oxygen
D) aluminum
E) magnesium

Answer 1

silicon

Question 2

Write a note on the covalent character of elements in period two. Give examples to illustrate this phenomenon.

Answer 2

Because of the smaller atomic size, simple binary ionic compounds of second-period elements have more covalent character than the corresponding compounds formed from their heavier congeners. The very small cations derived from second-period elements have a high charge-to-radius ratio and can therefore polarize the filled valence shell of an anion. As such, the bonding in such compounds has a significant covalent component, giving the compounds properties that can differ significantly from those expected for simple ionic compounds. As an example, LiCl, which is partially covalent in character, is much more soluble than NaCl in solvents with a relatively low dielectric constant, such as ethanol (ε = 25.3 versus 80.1 for H₂O).

Question 3

Which of the elements from group 13 has a chemistry that is most similar to beryllium?

A) Boron
B) Aluminum
C) Gallium
D) Indium
E) Thallium

Answer 3

Aluminum

Question 4

Aluminum is chemically similar to silicon from group 14.

Question 5

Lithium is chemically most similar to _____.

A) sodium
B) potassium
C) hydrogen
D) beryllium
E) magnesium

Question 6

Which of the following elements has the greatest tendency to form multiple bonds in a compound?

A) Silicon
B) Nitrogen
C) Phosphorus
D) Sulfur
E) Selenium

Question 7

Which of the elements of group 13 will have the lowest bond strengths?

A) Boron
B) Aluminum
C) Gallium
D) Indium
E) Thallium

Question 8

The small size of boron prevents it from forming compounds in which it have more than four nearest neighbors. Thus, BF₃ forms the only coordinate the:

A) single-coordinate, mono BF⁻ ion.
B) double-coordinate, bent BF₂⁻ ion.
C) three-coordinate, trigonal BF₃⁻ ion.
D) four-coordinate, tetrahedral BF₄⁻ ion.
E) six-coordinate, octahedral BF₆^- ion.

Question 9

Which of the following members of group one exhibits the greatest covalent character when part of a simple binary compound?

A) Lithium
B) Sodium
C) Potassium
D) Rubidium
E) Cesium

Question 10

Due to their small radii, second-period elements have electron affinities that are _____ negative than would be predicted from general periodic trends.

Question 11

Lead is more likely than carbon to form compounds in the +4 oxidation state.

Question 12

Which element from group 13 is a semimetal?

A) Boron
B) Aluminum
C) Gallium
D) Indium
E) Thallium

Question 13

Which element from group 13 is more likely to form compounds in which it has a +1 oxidation state?

A) Indium
B) Boron
C) Gallium
D) Aluminum
E) Thallium

Question 14

Lithium chloride is more soluble than sodium chloride in solvents with a relatively low dielectric constant.

Question 15

What is the inert pair effect? Why is this effect observed?

Question 16

In moving down a group in the p-block, increasing ionization energies and _____ bond strengths result in an inert-pair effect.

Question 17

Nonmetals tend to gain electrons in chemical reactions to form compounds.

Question 18

_____ is the only nonmetal from group 14.

Question 19

Chlorine is more representative of halogens than fluorine.

Question 20

Nitrogen is chemically most similar to _____ from group 16.

Question 21

Hydrogen reacts with nonmetals, such as chlorine, to form ionic hydrides.

Question 22

Why can't D₂O or T₂O support life the same way H₂O does? What are tracers?

Question 23

How many protons does tritium have?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 24

A(n) _____ is an electrostatic interaction between a hydrogen bonded to an electronegative atom and an atom that has one or more lone pairs of electrons.

Question 25

Hydrogen is produced on an industrial scale by:

A) reacting active metals with a dilute acid.
B) reacting metals with a strong base.
C) the electrolysis of water.
D) reacting ionic hydrides with water.
E) catalytic steam reforming.

Question 26

In a(n) _____ bond formed by hydrogen, a hydride ion bridges two electropositive atoms.

Question 27

A covalent hydride differs from an ionic hydride in that the covalent hydride:

A) has a relatively high melting point.
B) decomposes to H₂(g) and the parent metal after heating.
C) is formed by hydrogen and less electropositive metals such as the transition metals.
D) is relatively volatile and has a low melting point.
E) is typically a nonvolatile solid in a lattice framework.

Question 28

Which element is likely to form a metallic hydride with hydrogen?

A) Cu
B) Na
C) Cl
D) K
E) Ba

Question 29

When an active metal like zinc is treated with a dilute acid, hydrogen is produced.

Question 30

Most of the elements in the periodic table form binary compounds with hydrogen, which are collectively referred to as _____.

Question 31

Which of the following ions contains a three center bond?

A) NH₄⁺
B) H₃O⁺
C) HSO₄^-
D) HCO₃
E) B₂H₇^-

Question 32

A hydrogen bond is a strong dipole interaction that results when H is bonded to very electropositive elements.

Question 33

Write a note on the isotopes of hydrogen.

Question 34

Hydrogen bonding is possible between the molecules of _____.

A) O₂
B) CO₂
C) H₂O
D) CH₄
E) O₃

Question 35

Hydrogen can form compounds by accepting an electron to form a(n) _____.

A) proton
B) hydronium ion
C) hydride ion
D) protium atom
E) hydrogen free radical

Question 36

The rarest isotope of hydrogen is _____.

Question 37

During the electrolysis of water, the gas evolved at the cathode is enriched in deuterium, while the remaining water is enriched in hydrogen.

Question 38

The normal boiling point of D₂O is greater than that of H₂O.

Question 39

Which element is likely to form an ionic hydride with hydrogen?

A) Se
B) C
C) O
D) N
E) Ca

Question 40

The most common isotope of hydrogen is _____.

A) proton
B) deuterium
C) tritium
D) protium
E) serium

Question 41

How are alkali metals recovered from their silicate ores?

Question 42

Which of the following solvents are alkali metals easily soluble in?

A) H₂O(l)
B) CCl₄(l)
C) NH₃(l)
D) C₂H₅OH(l)
E) C₂H₅CHO(l)

Question 43

In the isolation of lithium from its silicate ore, _____ is used to dissolve the lithium ion and Al³⁺ from the ore.

A) NaOH
B) Na₂CO₃
C) HCl
D) H₂SO₄
E) Cl₂

Question 44

_____ are cyclic polyethers that contain four or more oxygen atoms separated by two or three carbon atoms.

Question 45

Which of the following alkali metals has the shortest half-life?

A) Lithium
B) Potassium
C) Sodium
D) Cesium
E) Francium

Question 46

Which alkali metal reacts the slowest with water?

A) Lithium
B) Sodium
C) Potassium
D) Cesium
E) Francium

Question 47

_____ are more nearly spherical analogues of crown ethers and are even more powerful and selective complexing agents.

Question 48

Compounds that contain a metal covalently bonded to a carbon atom of an organic species are called_____.

Question 49

Which of the following compounds is more appropriate as a drying agent for an organic solvent?

A) Li₂SO₄
B) K₂SO₄
C) Cs₂SO₄
D) Fr₂SO₄
E) Rb₂SO₄

Question 50

Sodium is produced commercially from the reduction of NaCl by K, followed by the fractional distillation of Na(g).

Question 51

Cesium is denser than rubidium.

Question 52

Sodium reacts with carbon to produce a compound with the stoichiometry _____.

A) M₄C
B) M₂C₄
C) MC₈
D) M₂C₂
E) MC

Question 53

_____ is typically prepared by the electrolytic reduction of its molten chloride.

A) Lithium
B) Potassium
C) Rubidium
D) Cesium
E) Francium

Question 54

The standard reduction potentials (E°) of the alkali metals do not follow the trend based on ionization energies.

Question 55

Sodium is the strongest reductant among alkali metals.

Question 56

Li reacts with oxygen in air to give Li₂O₂.

Question 57

Write a note on the complex formation seen in alkali metals.

Question 58

_____ is the only alkali metal that reacts with atmospheric nitrogen to form its respective metal nitride.

A) Lithium
B) Sodium
C) Potassium
D) Cesium
E) Francium

Question 59

Alkali metals insert themselves between the sheets of carbon atoms to give new substances called _____.

Question 60

Which alkali metal reacts with oxygen (under normal conditions) to form a compound with the general formula M₂O_2, where M is the alkali metal?

A) Lithium
B) Sodium
C) Potassium
D) Rubidium
E) Francium

Question 61

Because of their higher ionization energy and small size, both Be and Mg form organometallic compounds.

Question 62

_____ will have the lowest first ionization energy.

A) Beryllium
B) Magnesium
C) Calcium
D) Strontium
E) Barium

Question 63

Two intertwined strands of DNA are connected by hydrogen bonds.

Question 64

In the group 2 of elements, only the oxide of _____ is amphoteric.

A) beryllium
B) magnesium
C) calcium
D) strontium
E) barium

Question 65

The group 2 elements almost exclusively form ionic compounds containing M²⁺ ions.

Question 66

BeO(s) + OH⁻(aq) + H₂O(l) →

A) Be₂O₂ + H₃O⁺
B) [Be(OH)₆]^4-
C) BeO₂ + OH^-
D) [Be(OH₄)]^2-
E) Be(s) + H₂(g)

Question 67

The density of Ca is _____ than that of Be and Mg

Question 68

Marie Curie was awarded the Nobel Prize in Chemistry in 1911 for the discovery of _____.

A) beryllium
B) magnesium
C) calcium
D) strontium
E) radium

Question 69

_____ of group 2 elements is highly radioactive.

Question 70

Hydroxides of the lighter alkaline earth metals are soluble in water and their solubility decreases as the atomic number of the metal increases.

Question 71

When heated, all alkaline earth metals, except for _____, react directly with carbon to form ionic carbides with the general formula MC2.

A) beryllium
B) magnesium
C) calcium
D) strontium
E) barium

Question 72

Which element from group two is the most electronegative?

A) Beryllium
B) Magnesium
C) Calcium
D) Strontium
E) Barium

Question 73

Write a note on organometallic compounds formed by group 2 elements.

Question 74

Ingestion of beryllium or exposure to beryllium-containing dust causes a syndrome called _____.

Question 75

Which alkaline earth metal does not react readily with nitrogen to form a nitride?

A) Beryllium
B) Magnesium
C) Calcium
D) Strontium
E) Barium

Question 76

Calcium carbide (CaC₂) reacts readily with water to produce acetylene.

Question 77

Of the carbonates formed from alkaline earth metals, _____ is a major component of cement and an ingredient in many commercial antacids.

Question 78

Which element from group 2 has the lowest density?

A) Beryllium
B) Magnesium
C) Calcium
D) Strontium
E) Barium

Question 79

Magnesium ions in an aqueous environment contain octahedral complexes.

Question 80

Which element from group two forms a peroxide instead of an oxide when reacted with oxygen?

A) Beryllium
B) Magnesium
C) Calcium
D) Strontium
E) Barium