CHEML 1010 Week 10
The valence shell electron pair repulsion (VSEPR) model _____.
describes the three-dimensional arrangement of the atoms in a molecule
Allotropes are _____.
different structural modifications of an element
Carbon dioxide has a _____ geometric structure.
linear
Valence electrons that are not shared between two atoms are called _____.
lone pairs
When a molecule has more than one interior atom, _____.
more than one geometry may be used to describe the molecule
SF6 has a _____ geometric structure.
octahedral
The goal of the VSEPR model is to arrange the position of the atoms and lone pairs surrounding the central atom in a manner that minimizes _____.
repulsion
The localized electron model assumes that a molecule is bonded through the _____.
sharing of valence electron pairs
bond: 4lone pairs: 0geometry:
tetrahedral
Molecular modeling kits are useful in determining the Lewis structure of a molecule.
False
Resonance occurs when there is only one option for the Lewis structure model.
False
The Lewis structure for H2O includes double bonds.
False
The duet rule is based upon the observation that atoms are most stable when surrounded by eight valence electrons.
False
The number of valence electrons of an atom can be found in the row number on the periodic table.
False
Valence electrons include all electrons of an atom.
False
Alkali metals are a group located at the far left of the periodic table; alkali metals have _____ valence electron(s).
1
Magnesium has _____ valence electrons.
2
The octet rule is based upon the observation that atoms are most stable when surrounded by how many valence electrons?
8
Move the terms to complete each statement.
A model that describes the three dimensional arrangement of electrons based on electron repulsion is called the VSEPR model. Two hydrogen atoms form a duet when they have covalent bonds. Diamond and graphite are two allotropes of carbon. Resonance structures show the same connection of atoms but different arrangement of the bonds. An atom that has less than eight electrons surrounding it in a compound is said to be electron deficient . The number of outermost electrons is the number of valence electrons .
Match the number of valence electrons with the correct compound. CH4 PBr3 OF2 CH2O O3 SiCl4
CH4= 8 PBr3= 26 OF2= 20 CH2O= 12 O3= 18 SiCl4= 32
The _____ of a molecule visually describes the two-dimensional arrangement of atoms and valence electrons in a molecule.
Lewis structure
What atoms always obey the octet rule?
Oxygen, fluorine, nitrogen, carbon
Some compounds have more than one Lewis structure.
True
The first step in creating a Lewis structure is to determine the total number of valence electrons for the entire molecule.
True
A model that describes the three dimensional arrangement of electrons based on electron repulsion is called the --_____ model.
VSEPR
Different structural modifications of an element are called _____.
allotropes
An example of an atom with 3 valence electrons is _____.
aluminum
bond: 2lone pairs: 2geometry:
bent
In a molecular modeling kit, a black ball with 4 holes most likely represents the element _____.
carbon
bond: 3lone pairs: 0geometry:
trigonal planar
bond: 3lone pairs: 1geometry:
trigonal pyramidal