Chemistry Semester Final Review 2023-24

What is a Lewis valence e-dot structure?

• a representation of the valence electrons arranged around the nucleus of an atom

• a model to predict the mass of the molecule

• a representation of the protons in an atom

• a list of where all the electrons are located in an atom

How would you draw a Lewis dot diagram for the following atom of Arsenic. 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3

• 
• 
• 
• 

Which of the following is the correct e-dot diagram?

• 
• 
• 
• 

Which particles are represented by the dots in Lewis valence e-dot structures?

• core electrons

• valence electrons

• protons

• all electrons

What is the ground state electron configuration for arsenic?

• 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3

• 1s2 2s2 2p6 3s2 3p6 4s2 4p3 4d10

• 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6

• 1s2 2s2 2p6 3s2 3p6 4s2 4p3

Which element has the ground state electronic configuration, 1s2 2s2 2p6 3s2 3p6 4s1?

• calcium

• potassium

• phosphorus

• bromine

Which of the following molecules has a central atom with precisely two unshared pairs of electrons?

• ammonia NH3

• methane CH4

• water H2O

• hydrocyanic acid HCN

Around the central atom in a covalently bonded molecule, there are four pairs of electrons: three shared pairs and one unshared pair. The geometry of this molecule is best described as —

• linear

• trigonal planar

• trigonal pyramidal

• tetrahedral

Which of the following molecules would be expected to exhibit a tetrahedral geometry?

• NH3

• CH2O

• H2O

• CH4

The following picture shows a covalent molecule. What molecule listed below has the same shape?

• BH₃

• H₂O₂

• NH₃

• Na₃P