Ions, Chemical Bonding, and Ionic Nomenclature

Comprehensive practice flashcards covering ions, electron transfer, types of chemical bonds, binary ionic nomenclature, transition metal compounds, and polyatomic ionic formulas.

What makes an atom neutral according to atomic structure notes?

An atom is neutral when it has the same number of protons ($+$) and electrons ($-$), so the charges cancel each other out.

What is an ion, and how does an atom obtain a charge?

An ion is an atom with a different number of electrons compared to protons. It obtains a positive ($+$) or negative ($-$) charge by losing or gaining electrons.

Why can an atom only gain or lose electrons, rather than protons, to form an ion?

Because if an atom loses or gains protons, it becomes a new element.

What is a cation, and what types of elements typically form them?

A cation is a positive ion formed when an atom loses electrons. Metals and hydrogen (located on the left side of the periodic table) typically form cations.

What is an anion, and what types of elements typically form them?

An anion is a negative ion formed when an atom gains electrons. Nonmetals (located on the right side of the periodic table) typically form anions.

In element shorthand notation, what do the values positioned at the top-left, bottom-left, and top-right of the symbol represent?

The top-left is the atomic mass (number of protons AND neutrons), the bottom-left is the atomic number (number of protons), and the top-right is the net charge ($+$) if losing electrons, $-$) if gaining electrons).

If an element has $17$ protons and $18$ electrons, what is the charge on the ion and what is its symbol?

The charge is $-1$, and the symbol is $\text{Cl}^-$.

If an element has $20$ protons and $18$ electrons, what is the charge on the ion and what is its symbol?

The charge is $+2$, and the symbol is $\text{Ca}^{2+}$.

What are valence electrons?

Valence electrons are the electrons located on the outermost ring or orbital of an atom; they are the electrons that an atom will gain, lose, or share.

How is the number of valence electrons an atom has determined using the periodic table?

By using the last digit of the group number (the top numbers of the vertical columns).

What must the total net charge of any chemical compound always equal?

The total net charge of compounds will always equal zero ($0$).

What does an oxidation number tell you about an atom?

It tells the total number of electrons that an atom can gain or lose to form a chemical bond with another atom and become stable as a charge.

What is the Octet Rule?

The rule stating that atoms will gain, lose, or share electrons until they obtain $8$ valence electrons on their outermost energy level to become stable.

Which two elements are exceptions to the octet rule because they only need $2$ electrons to be stable?

Hydrogen and Helium.

Why are noble gases chemically unresponsive and stable?

They already have a full octet (a full outer energy level of electrons).

What is a chemical bond, and why do atoms form them?

A chemical bond is the attractive force between the valence electrons of different atoms that binds them together. Atoms form bonds to become more stable by filling their outer energy level.

What occurs during the formation of an ionic bond?

Electrons are transferred from a metal to a nonmetal, with one atom losing electrons and the other gaining electrons.

What are the key physical properties of ionic compounds?

They form crystal lattice structures (crystalline solids), are solid at room temperature, hard but brittle, have high melting and boiling points, are soluble in water, and exhibit electrical conductivity in aqueous solutions.

What occurs during the formation of a covalent bond?

Atoms share electrons, which can result in polar or nonpolar bonds.

What type of structure characterizes metallic bonding, and how do electrons behave?

Metallic bonding forms a "sea of electrons" structure where electrons are delocalized among surrounding metal atoms.

What are the characteristic properties of metallic bonds?

They are solid at room temperature, have high melting and boiling points, are not soluble in water, conduct electricity in any form, and are malleable, ductile, and lustrous.

What are binary ionic compounds composed of?

They are formed when one atom loses electrons (usually a metal to form a cation) and one atom gains electrons (usually a nonmetal to form an anion).

What do subscripts in a chemical formula represent?

They are the small numbers that come after symbols at the bottom; they indicate how many of each atom are present in the compound.

What are the steps for writing binary ionic formulas using the "criss-cross" method?

1. Write the metal symbol first (left). 2. Write the nonmetal symbol second (right). 3. Write each charge. 4. Criss-cross the charges across and down. 5. Write the charges as subscripts (without $+$ or $-$). 6. Reduce to least common multiples, omitting the number $1$.

What is the formula for the compound formed between aluminum ($\text{Al}^{3+}$) and oxygen ($\text{O}^{2-}$)?

$$\text{Al}_2\text{O}_3$$

What is the formula for the compound formed between magnesium ($\text{Mg}^{2+}$) and oxygen ($\text{O}^{2-}$)?

$\text{MgO}$ (the criss-crossed subscripts $2:2$ reduce to $1:1$).

What are the two rules for naming a binary ionic compound?

1. Name the first element (the metal). 2. Name the second element in its shortened form followed by the suffix "-ide" (usually shortened after the first or second vowel).

What is the correct systematic name for $\text{Ca}_3\text{N}_2$?

Calcium nitride

What is the correct systematic name for $\text{Na}_3\text{P}$?

Sodium phosphide

Why do transition metals (Groups 3–12) require Roman numerals in their names?

Because they can lose more than just their valence electrons, causing their positive charges to vary; the Roman numeral indicates the specific positive charge of the transition metal.

Which transition metal elements are exceptions that do NOT use Roman numerals?

Zinc ($\text{Zn}^{2+}$), Cadmium ($\text{Cd}^{2+}$), and Silver ($\text{Ag}^+$), because their charges do not vary.

Which two metals are NOT transition metals but still require Roman numerals because their charges vary?

Tin ($\text{Sn}$) and Lead ($\text{Pb}$).

What is the chemical formula for Iron (III) oxide?

$$\text{Fe}_2\text{O}_3$$

How do you determine the Roman numeral for the transition metal in $\text{PbCl}_4$?

Un-criss-cross the subscripts: since Chlorine has a $-1$ charge and there are $4$ chlorides (total $-4$), Lead must have a charge of $+4$, making it Lead (IV) chloride.

What is the difference in nomenclature between $\text{CuCl}$ and $\text{CuCl}_2$?

$\text{CuCl}$ is Copper (I) chloride (where copper is $+1$), and $\text{CuCl}_2$ is Copper (II) chloride (where copper is $+2$).

What is a polyatomic ion?

A group of covalently bonded atoms that together have an overall charge (the prefix "poly-" means many).

Which polyatomic ion is a positively charged cation and written on the left in formulas?

Ammonium ($\text{NH}_4^+$).

When writing formulas for polyatomic ionic compounds, when must parentheses be used?

If the polyatomic ion needs a subscript greater than $1$, write the symbols inside parentheses and place the subscript on the outside.

What is the chemical formula for calcium hydroxide?

$$\text{Ca}(\text{OH})_2$$

What is the chemical formula for beryllium phosphate?

$$\text{Be}_3(\text{PO}_4)_2$$

What are the nomenclature rules when naming a polyatomic ionic compound?

Name the first metal (or ammonium). Then name the second polyatomic ion without changing its ending; if ammonium is paired with a single nonmetal, shorten the nonmetal and end it with "-ide".

What is the systematic name for the compound $(\text{NH}_4)_2\text{S}$?

Ammonium sulfide

What is the name and formula of the polyatomic cation with a $1+$ charge composed of hydrogen and oxygen?

Hydronium, with the formula $\text{H}_3\text{O}^+$.

How does naming differ when $\text{O}_2$ is bonded with a nonmetal versus a metal or hydrogen?

$\text{O}_2$ paired with a nonmetal is called "dioxide", whereas $\text{O}_2^{2-}$ paired with a metal or hydrogen (acting as a metal) is the polyatomic ion "peroxide".