Intro to Chemical bonds
Ionic bonds form as a result of the electrostatic attraction between a. dipoles. b. electrons. c. ions. d. nuclei.
c
The electrons involved in the formation of a covalent bond are a. transferred from one atom to another. b. found only in the s orbitals. c. valence electrons. d. in filled orbitals.
c
The salts NaCl(s) and CaCl2(s) a. are good conductors of electricity. b. are positively charged. c. are held together by ionic bonds. d. Both (a) and (b)
d
VSEPR theory a. predicts the shape of some molecules. b. is limited to polar molecules. c. assumes that pairs of valence electrons surrounding an atom repel each other. d. Both (a) and (c)
d
The charge on an ion is a. always positive. b. always negative. c. either positive or negative. d. zero.
c
A single covalent bond involves the sharing of a. only one electron. b. two electrons. c. three electrons. d. a variable number of electrons, which depends on the bonding atoms.
b
Bond energy is the energy a. absorbed as a molecule forms. b. change as atoms get closer together. c. required to break a chemical bond and form separate, neutral atoms. d. of two covalently bonded atoms.
c
Compared with solid ionic compounds, solid molecular compounds generally a. have lower melting points. b. are more brittle. c. are harder. d. conduct electricity as liquids.
a
The shape of molecules that contain only two atoms is a. linear. b. bent. c. trigonal planar. d. Either (a) or (b)
a
According to the octet rule, a calcium atom has a tendency to a. lose one electron. b. lose two electrons. c. gain one electron. d. gain two electrons.
b
Use the table below to choose the pair of elements that will most likely have the least ionic character. Element Electronegativity Na 0.9 O 3.5 Cl 3.0 H 2.1
a. Na and Cl b. O and Cl c. H and O d. Na and O
b
If two covalently bonded atoms move closer than a distance of the bond length, the potential energy of the atoms a. becomes negative. b. decreases. c. increases. d. remains constant.
c
A charged group of covalently bonded atoms is known as a(n) a. anion. b. polyatomic. c. formula unit. d. cation.
b
According to VSEPR theory, which molecule has a bent shape? a. CO2 b. H2O c. CS2 d. HF
b
Which formula listed below represents a polyatomic ion? a. – HCO3 b. H2SO4 c. Cl– d. Na
a
Atoms that are bonded with an electronegativity difference of 0 to 0.3 are generally considered to be a. negatively charged compounds. b. nonpolar-covalent compounds. c. polar-covalent compounds. d. ionic compounds.
b
Which compound most likely has the greatest bond energy?
a. HF; H⎯F bond length = 92 pm
b. I2; I⎯I bond length = 266 pm
c. Cl2; Cl⎯Cl bond length = 199 pm
d. HCl; H⎯Cl bond length = 127 pm
a
Chemical bonding in metals is a. the same as ionic bonding. b. the same as covalent bonding. c. a combination of ionic and covalent bonding. d. different from ionic or covalent bonding
d
VSEPR theory predicts that the shape of carbon tetrachloride, CCl4, is a. linear. b. bent. c. trigonal planar. d. tetrahedral (diamond)
d
Two atoms will likely form a polar covalent bond if the electronegativity difference is a. 0.1. b. 1.0. c. 2.5. d. 4.0.
b
Use the table below to choose the pair of elements that will most likely have the greatest ionic character. Element Electronegativity K 0.8 N 3.0 Br 2.8 S 2.5
a. K and N b. K and S c. N and Br d. S and Br
a
To draw a Lewis structure, it is not necessary to know a. the length of the bonds. b. the types of atoms in the molecule. c. the number of valence electrons for each atom. d. the number of atoms in the molecule.
a
The valence electrons in a metallic bond a. move freely throughout the network of metal atoms. b. are held tightly by the most positively charged atom. c. are shared equally between two metal atoms. d. continuously move from one energy level to another.
a
A covalent bond is formed when two atoms a. share an electron with each other. b. share one or more pairs of electrons with each other. c. gain electrons. d. gain and lose electrons.
b
In the movie, First man, Armstrong gets a job with NASA. What city did he end up moving to for this job?
Houston,TX