Question 1

Which of the following compounds has only covalent bonding?

Accepted Answer

Covalent bonding occurs between non-metal atoms, and compound A contains only non-metal elements (H, S, and O) bonded together through covalent bonding. The other choices contain at least one metal element, which typically form ionic bonds with non-metals.

Question 2

Cl^- is a(n) _____ ion.

Accepted Answer

monoatomic

Question 3

Differentiate between organic and inorganic compounds.

Accepted Answer

Covalent compounds that contain predominantly carbon and hydrogen are called organic compounds. Compounds that consist primarily of elements other than carbon and hydrogen are called inorganic compounds; they include both covalent and ionic compounds.

Question 4

Which of the following is an elemental-polyatomic molecule?

Accepted Answer

Phosphorous commonly exists as P4, which is a polyatomic molecule consisting of a single element, making it an elemental-polyatomic molecule.

Question 5

How many electrons are shared between two atoms joined by a double bond?

Accepted Answer

In a double bond, two atoms share four electrons, with each atom contributing two electrons to the bond.

Question 6

In a(n) _____, the atoms are held together by the electrostatic attraction between the positively charged nuclei of the bonded atoms and the negatively charged electrons they share.

Accepted Answer

The answer of In a(n) _____, the atoms are held...

Question 7

In an ionic bond, the atoms are held together by the electrostatic attraction between the positively charged nuclei of the bonded atoms and the negatively charged electrons they share.

Accepted Answer

In an ionic bond, atoms are held together by the electrostatic attraction between positively charged ions (cations) and negatively charged ions (anions), not by sharing electrons as described.

Question 8

What is a chemical bond? Briefly describe the types of chemical bonds.

Accepted Answer

The answer of What is a chemical bond? Briefly describe...

Question 9

If two charged particles, Q₁ and Q₂, are separated by the distance r, the electrostatic energy between the particles is $\infty$ _____

Accepted Answer

The correct formula for the electrostatic energy (potential energy) between two charged particles is given by $ \frac { k \cdot Q _ { 1 } Q _ { 2 } } { r } $, where $Q_1$ and $Q_2$ are the charges, $r$ is the distance between them, and $k$ is Coulomb's constant. Option D, represented as $ \frac { Q _ { 1 } Q _ { 2 } } { r } $ (with the constant $k$ omitted for simplicity), correctly reflects this relationship.

Question 10

Methane (CH₄) is a covalent molecule, where electrons are shared between the carbon and hydrogen atoms.

Accepted Answer

Covalent molecules are formed by sharing of electrons between atoms, which is exactly the case with methane where carbon shares its electrons with hydrogen to form covalent bonds.

Question 11

Each covalent compound is represented by a(n) _____ , which gives the atomic symbol for each component element, in a prescribed order, accompanied by a subscript indicating the number of atoms of that element in the molecule.

Accepted Answer

The answer of Each covalent compound is represented by a(n)...

Question 12

Which of the following is an organic compound?

Accepted Answer

Organic compounds must contain carbon, and only choice C contains carbon. The other choices are inorganic compounds.

Question 13

Which method of representing the structure of a molecule uses wedges and dashes to sketch the structure of a molecule in three dimensions?

Accepted Answer

Perspective drawing is the method of representing the structure of a molecule using wedges and dashes to sketch the structure of a molecule in three dimensions. In this method, the solid lines represent bonds that come out of the plane towards the viewer, the dashed lines represent bonds that go behind the plane away from the viewer, and the wedged lines represent bonds that come out of the plane towards the viewer. This allows for a three-dimensional representation of the molecule that shows the relative positions of the atoms in space.

Question 14

Which of the following molecules has a tetrahedral geometry?

Accepted Answer

A tetrahedral geometry means that the central atom has four bonded atoms or lone pairs arranged around it, creating a shape similar to a pyramid with a triangular base. In molecule choice C, carbon has four different bonded atoms (one hydrogen and three carbon), which results in a tetrahedral geometry. The other molecules do not have this arrangement of atoms, and therefore do not have a tetrahedral geometry.

Question 15

Ions that contain more electrons than protons have a net negative charge and are called _____.

Accepted Answer

The answer of Ions that contain more electrons than protons...

Question 16

The most common monoatomic ion formed by magnesium is _____.

Accepted Answer

The correct formula for the most common monoatomic ion formed by magnesium is Mg2+. This can be determined by knowing the charge on the magnesium ion (2+) and knowing that monoatomic ions have no overall charge. Choice D is the only option that contains Mg2+.

Question 17

There is a triple bond between the two oxygen atoms in a molecule of O₂.

Accepted Answer

The molecule O₂ is not a valid chemical formula, it does not represent any known compound. Therefore, it is impossible to determine if there is a triple bond between the two oxygen atoms in this molecule.

Question 18

A Ca²⁺ion has the same number of electrons as the noble gas Argon.

Accepted Answer

CaS1U1P12 is Calcium (Ca) with one sulfur (S) atom, one uranium (U) atom, and 12 phosphorus (P) atoms. S1S1P0S1U1B1 is one sulfur atom, one phosphorus atom, and one boron atom. Together, they form CaS1U1P12S1U1B1, which has the same number of electrons as Argon, a noble gas with the electron configuration 1s2 2s2 2p6 3s2 3p6.

Question 19

What is the total number of electrons present in an Mg²⁺ ion?

Accepted Answer

An Mg atom has 12 electrons. When it loses 2 electrons to form an Mg²⁺ ion, it has 10 electrons remaining.

Question 20

Ions that contain fewer electrons than protons have a net positive charge and are called anions.

Accepted Answer

Ions with more protons than electrons have a net positive charge and are called cations, whereas anions have more electrons and therefore have a net negative charge.

Quiz 2: Molecules, Ions, and Chemical Formulas