Electronegativity
What is electronegativity?
how strongly an atom attracts electrons in a bond?
A molecule with an uneven distribution of charge is called what?
Polar molecule
The number of protons in an atom is known as what?
The atomic number.
Where are valence electrons found?
Each dot in a Lewis Dot Diagram represents one of these.
Valence electrons.
What is the element with the highest electronegativity?
Fluorine
A polar bond forms when this difference in electronegativit exists between atoms.
0.4-1.7
What region of the atom contains nearly all of its mass?
The nucleus.
What is the maximum number of electrons in the first shell?
2
Explain why, in terms of coulombs law, why across (left to right) a period the electronegativity increases.
Across a period, electronegativity increases because of Coulomb’s Law, which states that the attraction between charged particles increases when the charges are larger and the distance between them is smaller.
As you move left to right across a period:
The nuclear charge increases (more protons in the nucleus).
The distance to the valence electrons stays about the same because electrons are being added to the same energy level.
Electronegativity generally increases in what direction across a period?
left to right.
In a water molecule, the partial negative charge is found on which atom?
Oxygen
What term describes an atom with a different number of electrons than protons?
Ion.
How many valence electrons are in a fluorine atom?
7
How many electron shells does an atom of Bromine (Br) have?
4
Between Carbon, Nitrogen, and Oxygen, which element is the most electronegative?
Oxygen
If Carbons electronegativity is 2.6 and Oxygens electronegativity is 3.4, what type of bond will these atoms form?
Polar Covalent bond.
What is the spacce that electrons occup around the nucleus called?
energy levels or shells
These are the particles that element in the same group all have the same number of.
Valenece electrons
According to Coulomb’s law, increasing the distance between charged particles does what to attraction?
decreases attraction
Explain in terms of electronegativity, why polar bonds result in partial charges while nonpolar bonds result in no charge.
In a polar bond, the atoms have different electronegativities, so the more electronegative atom pulls the shared electrons closer to itself. This causes it to gain a partial negative charge (δ–). The less electronegative atom loses some electron density and becomes partial positive (δ+). In a nonpolar bond, the atoms have equal or nearly equal electronegativities, so they pull on the shared electrons equally. Because the electron density is evenly distributed, no partial charges form.
Nonpolar covalent bonds: Electrons are shared equally between the two atoms.
Polar covalent bonds: Electrons are shared unequally because one atom attracts the electrons more strongly.
Ionic bonds: Electrons are transferred from one atom to another, creating positive and negative ions that attract each other.
The mass number is the sum of which subatomic particles?
Protons and neutrons.
Explain in terms of valence electrons, why group 18 elements are known as noble gases.
Group 18 elements are known as noble gases because their atoms have full valence electron shells.
With a complete outer shell (usually 8 valence electrons, except helium with 2), they are already stable and do not need to gain, lose, or share electrons.
Explain, using Coulombs law and electron shells, why going down a group decreases electronegativity.
Going down a group, electronegativity decreases because of the increasing distance between the nucleus and the valence electrons and increased shielding, which reduce the nucleus’s ability to attract shared electrons. Coulomb’s Law states that the attraction between charged particles decreases when the distance between them increases.