Unit 7 test

Question 1

What is the octet rule?

Answer 1

Atoms tend to gain, lose, or share electrons to achieve a full outer shell of eight electrons

The octet rule is a key concept in understanding chemical bonding and stability.

Question 2

What are delocalized electrons?

Answer 2

Electrons that are not associated with a single atom or bond and can move freely within a structure, often described as a sea of electrons

This concept is important in explaining the conductivity and malleability of metals.

Question 3

What is an ionic bond?

Answer 3

A type of chemical bond formed through the electrostatic attraction between oppositely charged ions

Ionic bonds typically form between metals and non-metals.

Question 4

How is an ionic bond formed?

Answer 4

Through the transfer of electrons from one atom to another, resulting in the formation of cations and anions

This process usually occurs between a metal and a non-metal.

Question 5

What is a covalent bond?

Answer 5

A type of chemical bond formed when two atoms share one or more pairs of electrons

Covalent bonds typically form between non-metal atoms.

Question 6

How is a covalent bond formed?

Answer 6

Through the sharing of electron pairs between two atoms

This sharing allows both atoms to achieve a stable electron configuration.

Question 7

What is a salt?

Answer 7

ionic compounds that do not start with H nor end with OH

Common table salt is sodium chloride (NaCl).

Question 8

What does isoelectronic mean?

Answer 8

Having the same number of electrons or the same electronic structure as another atom or ion

Isoelectronic species often have similar chemical properties.

Question 9

What is electrostatic force?

Answer 9

The attraction or repulsion between charged particles

This force is responsible for the formation of ionic bonds.

Question 10

What is a cation?

Answer 10

A positively charged ion that has lost one or more electrons

Cations are typically formed from metals.

Question 11

What is an anion?

Answer 11

A negatively charged ion that has gained one or more electrons

Anions are typically formed from non-metals.

Question 12

What is a formula unit?

Answer 12

The smallest unit of an ionic compound

It represents the simplest form of the compound’s formula.

Question 13

What is a molecule?

Answer 13

A group of two or more atoms bonded together by covalent bonds

Molecules can consist of the same or different elements.

Question 14

What is an alloy?

Answer 14

A mixture of two or more metals, or a metal and another element

Alloys often exhibit enhanced properties compared to their component metals.

Question 15

What is an amalgam?

Answer 15

An alloy of mercury with another metal

Amalgams are commonly used in dental fillings.

Question 16

What are the two ways that atoms can achieve stability?

Answer 16

1. Gaining, losing, or sharing electrons
2. Achieving a full outer shell of electrons

These processes are fundamental for the formation of chemical bonds.

Question 17

How can you determine the charge on an ion?

Answer 17

By considering the number of electrons lost or gained by an atom

The charge can be deduced from the atom’s position in the periodic table.

Question 18

What are the properties of ionic compounds?

Answer 18

1. High melting and boiling points
2. Soluble in water
3. Conduct electricity when dissolved or molten

These properties are due to strong ionic bonds and the ability of ions to move in solution.

Question 19

How do you write formulas for ionic compounds?

Answer 19

By combining the symbols of the cation and anion, ensuring the total charge is neutral

The ratio of ions is determined by their charges.

Question 20

How do metals bond and what properties do they have?

Answer 20

Metals bond through metallic bonds characterized by a sea of delocalized electrons, leading to properties such as malleability and conductivity

This bonding structure allows metals to conduct electricity and heat efficiently.

Question 21

Which elements need Roman numerals in a name and why?

Answer 21

Elements that can form more than one type of ion, typically transition metals, need Roman numerals to indicate their charge

This ensures clarity about the specific ion being referred to in a compound.