5.5,5.6,5.10 Flashcards
(27 cards)
What is an atom?
An atom is an electrically neutral particle with an equal number of electrons and protons.
What is an ion?
An ion is an atom that has become charged by gaining or losing one or more electrons.
- Ex. NA loses one electron to become a Cation with a +1 charge
- Ex. F gains one electron to become an Anion with a -1 charge
What is a cation?
A cation is a positively charged ion.
- Example: Sodium loses one electron to become a cation with a +1 charge.
What is an anion?
An anion is a negatively charged ion.
- Example: Fluorine gains one electron to become an anion with a -1 charge.
How do we represent the charge of CATIONS/ metals that turn into them?
EX. We say the charge on sodium (CATION) is +1 but we write the ion as Na+.
How do we represent the charge of ANIONS/ NON- metals that turn into them?
We say the charge on fluorine is -1 but we write the ion as F-.
What is the naming convention for positive vs negative ions?
The name of a positive ion is the same as the name of the element: sodium atom, sodium ion
The name of a negative ion is determined by adding ‘ide’ to the stem of the name: fluorine, fluoride ion
How many electrons do NON- metals have in their outer orbit?
NON- metals have five, six, or seven electrons in their outer orbit.
What do metals tend to do with their outer electrons?
Metals have one, two, or three electrons in their outer orbit. They tend to lose these electrons to become more stable and form a positive ion (cation).
How many electrons do metals have in their outer orbit?
Metals have one, two, or three electrons in their outer orbit.
What do non-metals tend to do with their outer electrons?
Non-metals have five, six, or seven electrons in their outer orbit. They tend to gain electrons to fill their outer orbit and become more stable, forming a negative ion (anion).
What does it mean for an atom to be isoelectronic with a noble gas?
When an atom forms an ion, it can become isoelectronic with a noble gas, meaning it has the same number of electrons as the noble gas.
Which noble gas is sodium isoelectronic with?
Sodium (Na) becomes isoelectronic with neon (Ne) after it LOSES an electron.
Sodium origionally has 11 electrons, but as a metal, it loses one electron in order to achieve a more stable electron configuration. When sodium loses an electron, it forms a Na⁺ ion, which now has only 10 electrons, just like neon, a noble gas that has 10 electrons. This is why the sodium ion (Na⁺) is isoelectronic with neon (Ne).
Which noble gas is fluorine isoelectronic with?
Fluorine (F) becomes isoelectronic with neon (Ne) after it GAINS an electron.
Fluorine origionally has 9 electrons, but as a NON- metal, it GAINS one electron in order to achieve a more stable electron configuration. When fluorine GAINS an electron, it forms a fluoride ion (F⁻) with 10 electrons, which is the same number of electrons as neon, a noble gas that has 10 electrons.
What are Lewis Diagrams?
Lewis Diagrams are representations of the atom that only show the valence electrons, drawn as dots around the symbol for the element.
How can Lewis diagrams be used?
Lewis diagrams can be used to show the bonds in ionic compounds.
Example of using Lewis diagrams for ionic compound?
Use Lewis diagrams to show the bonding in magnesium fluoride (MgF2).
Example of using Lewis diagrams for mulecular compound?
Use Lewis diagrams to show the bonding in hydrogen gas (H2).
How do you represent a covalent bond in a Lewis diagram?
To represent the covalent bond in a Lewis diagram, we use a line, which represents two shared electrons (or a pair).
What do the brackets [..] around an element represent in an ionic compound in a lewis structure eg. [Mg]?
The brackets []around an element represent the ion formed when the atom gains or loses electrons.
* The brackets help show the charge on the ion and are used to distinguish the ion from its neutral atom form as seen below.
The charge on the ion is indicated as a superscript outside the brackets. For example:
[Mg]²⁺ represents a magnesium ion (Mg²⁺) with a +2 charge.
[O]²⁻ represents an oxide ion (O²⁻) with a -2 charge.
In covalent compounds, the atoms share electrons, so brackets are not needed, as no ions are formed.
In covalent compunds, do we use the brackets around an element why or why not?
In covalent compounds, the atoms share electrons, so brackets are NOT needed, as no ions are formed.
How would you draw the Lewis diagram for a molecule of water (H₂O)?
H−O−H
In water (H₂O), oxygen shares electrons with two hydrogen atoms.
- Oxygen (O) has 4 visible dots (representing 2 lone pairs) and shares 2 electrons with each hydrogen atom (represented by the lines).
- Hydrogen (H) has 1 dot (representing its single valence electron) and shares that electron with oxygen.
Oxygen achieves 8 electrons in its valence shell, and each hydrogen achieves 2 electrons in its valence shell (by sharing).
What do the dots, lines, and brackets represent in Lewis diagrams?
- Dots (.) represent valence electrons (unshared).
- Lines (–) represent shared electrons in a covalent bond.
1 line (–) = 2 electrons (single bond).
2 lines (=) = 4 electrons (double bond). - Brackets [ ] with a charge represent ions in ionic bonds, showing the electron loss or gain.
[Na]⁺ = Sodium ion (Na) has lost 1 electron.
[Cl]⁻ = Chlorine ion (Cl) has gained 1 electron.
Flashcard 2: Ionic Bonding (Sodium Chloride, NaCl)
Front:
What is the Lewis diagram for the formation of sodium chloride (NaCl)?
Back:
In sodium chloride (NaCl), sodium (Na) loses one electron, and chlorine (Cl) gains that electron. The correct Lewis diagrams are:
Sodium (Na):
Na
→
[
Na
]
+
Na→[Na]
+
Sodium loses its single electron (represented as a dot), forming Na⁺. It now has no valence electrons.
Chlorine (Cl):
[
Cl
]
−
[Cl]
−
Chlorine gains one electron (represented as a dot), completing its octet (8 electrons in the valence shell).
The Na⁺ and Cl⁻ ions are held together by ionic bonds due to electrostatic attraction.
