Question 1

A chemical compound formed from lithium and chlorine should be ionic in character.

Accepted Answer

When an alkali metal reacts with a halogen, like lithium with chlorine, they form an ionic compound with the metal giving away an electron to form a cation and the halogen accepting the electron to form an anion. Therefore, the compound formed from lithium and chlorine should be ionic in character.

Question 2

Covalent bonds are formed between atoms that share pairs of electrons.

Accepted Answer

Covalent bonds are formed by the sharing of electrons between atoms. The shared electrons are called a bonding pair, and each atom contributes one electron to the pair.

Question 3

The electrons in a carbon-chlorine covalent bond are "shared" exactly equally between these two atoms.

Accepted Answer

Electronegativity of Chlorine is higher than Carbon, hence Chlorine pulls the bonding electron pair more towards itself resulting in unequal sharing of electrons.

Question 4

A single bond is always represented by two electrons.

Accepted Answer

A single bond involves the sharing of one pair of electrons between two atoms, which is represented as a single line in chemical structures. As one shared electron comes from each atom, a single bond is always represented by two electrons.

Question 5

Fluorine is the most electronegative element in the periodic table.

Accepted Answer

Fluorine has the highest electronegativity value of 3.98 on the Pauling scale, making it the most electronegative element in the periodic table.

Question 6

Carbon tetrafluoride has ________ total valence electrons.

Accepted Answer

Carbon has 4 valence electrons and there are 4 fluorine atoms, each contributing 7 valence electrons. Therefore, the total valence electrons in carbon tetrafluoride is 4 + 4(7) = 32.

Question 7

A single, neutral chlorine atom has seven valence electrons.

Accepted Answer

Chlorine has 7 valence electrons because it is in Group 17 (also known as Group VIIA or the halogens) of the periodic table, which means it has 7 electrons in its outermost energy level.

Question 8

The most electronegative element is oxygen.

Accepted Answer

Fluorine is the most electronegative element, not oxygen.

Question 9

The compound P₂O₅ has the name diphosphorus pentaoxide.

Accepted Answer

The compound P₂O₅ is correctly named diphosphorus pentoxide, which has the chemical formula P2O5.

Question 10

Water, H₂O and hydrogen peroxide, H₂O₂, have identical properties.

Accepted Answer

Water and hydrogen peroxide have similar chemical formulas (H2O and H2O2), but their properties are not identical. Hydrogen peroxide is a strong oxidizing agent and can be corrosive, while water is not.

Question 11

The chemical compound whose formula is Na₂S has the chemical name sodium sulfate.

Accepted Answer

The chemical formula given does not match that of sodium sulfate. The correct formula for sodium sulfate is Na2SO4.

Question 12

Energy is released as two atoms, such as two hydrogen atoms, form, a bond.

Accepted Answer

When two atoms bond together, energy is released as a result of the formation of a more stable molecule. This is true for most bond types, including the formation of a covalent bond between two hydrogen atoms.

Question 13

Compounds formed from carbon and hydrogen should be ionic in character.

Accepted Answer

Compounds formed from carbon and hydrogen, also known as hydrocarbons, typically have covalent bonding between the carbon and hydrogen atoms. This means that the electrons are being shared between the atoms, rather than transferred to form ions, making them non-ionic in character.

Question 14

Which of the following elements has at least two differently charged cations?

Accepted Answer

Cobalt has two different charged cations which are Co2+ and Co3+.

Question 15

Natural sugars are broken down into glucose in our body.

Accepted Answer

Natural sugars such as those found in fruit or honey are broken down into glucose in our body to be used as energy.

Question 16

How many resonance structure could be drawn for the nitrate ion?

Accepted Answer

The nitrate ion (NO3-) can have three resonance structures. These structures are formed by moving the double bond among the three oxygen atoms while the overall charge of -1 is maintained.

Question 17

The ion P^-³ is named phosphate.

Accepted Answer

The ion P^-3 is called phosphide, not phosphate. Phosphate is PO₄^3-.

Question 18

Metals are generally more electronegative than non-metals.

Accepted Answer

Metals are generally less electronegative than non-metals.

Question 19

The electronegativity of chlorine is 3.0 while that of iodine is 2.5. The correct way of writing the formula of a molecule composed of one chlorine and one iodine atoms and the corresponding name are ________.

Accepted Answer

When two non-metals combine to form a compound, the element with higher electronegativity is written first in the formula. Therefore, the correct way of writing the formula for a molecule composed of one chlorine and one iodine atom is ICl (not ClI). The corresponding name is iodine monochloride.

Question 20

When covalent bonds are broken energy is released.

Accepted Answer

When covalent bonds are broken, energy is required or absorbed, not released. Breaking a bond requires energy input, while forming a bond releases energy.

Quiz 5: Chemical Bonding and Nomenclature