MIDTERM REVIEW
Unit 1: Measurements and Lab Skills
1. A sample of an element has a mass of 34.261 grams and a volume of 3.8 cubic centimeters. To
which number of significant figures should the calculated density of the sample be expressed?
a) 5
b) 2
c) 3
d) 4
Unit 2: Matter and Energy
1. Which substance can be broken down by chemical means?
a) Ce
b) Cu
c) CO
d) Ca
2. Given the balanced equation representing a reaction:
CH4(g) + 2O2(g) ‚ 2H2O(g) + CO2(g) + heat
Which statement is true about energy in this reaction?
a) The reaction is exothermic because it absorbs heat.
b) The reaction is exothermic because it releases heat.
c) The reaction is endothermic because it absorbs heat.
d) The reaction is endothermic because it releases heat.
3. Which one of the following samples has particles with the lowest average kinetic energy?
a) 1.0 g of I2 at 50.°C
b) 7.0 g of I2 at 40.°C
c) 9.0 g of I2 at 20.°C
d) 2.0 g of I2 at 30.°C
4. A 36-gram sample of water has an initial temperature of 22 .°C. After the sample absorbs 1,200
joules of heat energy, what is the final temperature of the sample?
a) 55.°C
b) 14.°C
c) 8.0.°C
d) 30. °C
5. A beaker contains both alcohol and water. These liquids can be separated by distillation because
the liquids have different
a) densities
b) boiling points
c) solubilities
d) particle sizes
6. Which statement describes a chemical property of hydrogen gas?
a) Hydrogen gas has a boiling point of 20. K at standard pressure.
b) Hydrogen gas burns in air.
c) Hydrogen gas has a density of 0.00009 g/cm3 at STP.
d) Hydrogen gas is colorless.
7. Which process is a chemical change?
a) subliming of ice
b) decomposing of water
c) boiling of water
d) melting of ice
8. Which two physical properties allow a mixture to be separated by chromatography?
a) malleability and thermal conductivity
b) density and specific heat capacity
c) hardness and boiling point
d) solubility and molecular polarity
9. Which type of matter is composed of two or more elements that are chemically combined in a
fixed proportion?
a) compound
c) solution
b) heterogeneous mixture
d) homogeneous mixture
10. Which of the following two substances cannot be broken down by chemical change?
a) C and CuO
b) CO2 and Cu
c) C and Cu
d) CO2 and CuO
11. What Kelvin temperature is equal to 15.°C?
12. At room temperature, a mixture of sand and water can be separated by
a) sublimation
13.
b) combustion
c) filtration
d) ionization
A large sample of solid calcium sulfate is crushed into smaller pieces for testing. Which two
physical properties are the same for both the large sample and one of the smaller pieces?
a) solubility and volume
b) mass and volume
c) mass and density
d) solubility and density
14. Which one of the following formulas represents a mixture?
a) C6H12O6(l)
b) LiCl(aq)
c) LiCl(s)
d) C6H12O6(s)
15. Which type of energy is associated with the random motion of the particles in a sample of gas?
a) nuclear energy
b) thermal energy
c) electromagnetic energy
d) chemical energy
16. A person with a body temperature of 37.°C holds an ice cube with a temperature of 0DC in a
room where the air temperature is 20.°C. The direction of heat flow is
a) from the ice to the person and air, and from the air to the person
b) from the person to the ice and air, and from the air to the ice
c) from the ice to the person, only
d) from the person to the ice, only
Unit 3: Atomic Theory
1) What is the total number of valence electrons in an atom with the electron configuration 2-8-5?
a) 2
b) 5
c) 8
d) 15
2) A Ca2+ ion differs from a Ca0 atom in that the Ca2+ ion has
a) more electrons
b) more protons
c) fewer protons
d) fewer electrons
3) Which particles are referred to as nucleons (subatomic particles located in the nucleus)?
a) protons and neutrons
c) neutrons, only
b) protons and electrons
d) neutrons and electrons
4) What is the mass number of an atom that contains 19 protons, 19 electrons, and 20 neutrons?
a) 39
b) 19
c) 58
d) 20
5) What term refers to the region of an atom where an electron is most likely to be found?
a) quantum
b) spectrum
c) orbital
d) orbit
6) The nucleus of an atom consists of 8 protons and 6 neutrons. The total number of electrons present in a neutral
atom of this element is
a) 6
b) 8
c) 2
d) 1
7) What is the maximum number of electrons that can occupy the third principle energy level?
a) 18
b) 8
c) 10
d) 3
8) Atoms of 16O, 17O, and 18O have the same number of
a) protons, but a different number of electrons
c) protons, but a different number of neutrons
b) electrons, but a different number of protons
d) neutrons, but a different number of
protons
9) All atoms of an element have the same
a) number of neutrons
c) atomic number
b) atomic mass
d) mass number
10) The atomic number is always equal to the total number of
a) neutrons in the nucleus
c) neutrons plus protons in the atom
b) protons in the nucleus
d) protons plus electrons in the atom
11) How many protons are in the nucleus of an atom of beryllium?
a) 2
b) 4
c) 9
d) 5
12) Which subatomic particle is negative?
a) proton
b) neutron
d) nucleus
c) electron
13) Which of the following particles has the least mass?
a) neutron
b) proton
c) electron
d) hydrogen nucleus
14) What is the total number of electrons in an Mg+2 ion?
a) 10
b) 24
c) 2
d) 12
15) Which principal energy level of an atom contains an electron with the lowest energy?
a) 3
b) 4
c) 1
d) 2
Unit 4: Periodic Table
1) Which elements have the most similar chemical properties?
a) K and Na
b) K and Ca
c) K and Cl
d) K and S
2) Which element in Period 3 has the greatest tendency to gain electrons?
a) Ar
b) Cl
c) Si
d) Na
3) Which of the following elements has the highest ionization energy?
a) sodium
b) aluminum
c) calcium
d) phosphorus
4) In the modern Periodic Table, the elements are arranged according to
a) atomic mass
b) atomic number
c) mass number
d) oxidation number
5) As we move down the elements in Group 16, the electronegativity of the elements
a) increases
b) decreases c) remains the same
6) What element is in Group 2 and Period 7 of the Periodic Table?
a) magnesium
b) radon
c) manganese
d) radium
7) Alkali metals, alkaline earth metals, and halogens are found respectively in Groups
a) 1, 2, and 14
b) 1, 2, and 18
c) 1, 2, and 17
d) 2, 13, and 17
8) Compared to the atomic radius of a sodium atom, the atomic radius of a magnesium
atom is smaller. The smaller radius is primarily a result of the magnesium atom having
a) a smaller nuclear charge
c) a larger nuclear charge
b) fewer principal energy levels
d) more principal energy levels
9) Atoms of metallic elements tend to
a) gain electrons and form positive ions
c) lose electrons and form positive ions
b) lose electrons and form negative ions
d) gain electrons and form negative ions
10) Which element is considered a malleable substance?
a) sulfur
b) radon
c) hydrogen
d) gold
11) As we consider the elements of Period 2 from left to right, there is a general decrease in
a) ionization energy
b) metallic character
c) nonmetallic character
d) electronegativity
12) As we move down Group 1 elements of the Periodic Table, the first ionization energy of each element
decreases. One reason for this is that
a) the nuclear charge is decreasing
b) the number of principal energy levels is decreasing
c) the distance between the valence electron and the nucleus is increasing
d) the number of neutrons is increasing
13) The properties of boron are characteristic of
a) a metal only
b) a nonmetal only
c) both a metal and a nonmetal
d) neither a metal nor a nonmetal
14) Which compound contains an alkaline earth metal and a halogen?
a) CaS
b) Rb2S
c) RbCl
d) CaCl2
15) Which of the following generally applies to the noble gases?
a) high ionization energy, low electronegativity, high reactivity
b) high ionization energy, high electronegativity, high reactivity
c) low ionization energy, low electronegativity, low reactivity
d) high ionization energy, low electronegativity, low reactivity
Unit 5: Bonding
1. Given the balanced equation representing a reaction:
Cl2  Cl + Cl
What occurs during this reaction?
a) A bond is broken as energy is absorbed.
b) A bond is broken as energy is released.
c) A bond is formed as energy is absorbed.
d) A bond is formed as energy is released.
2. Which symbol represents a particle that has the same total number of electrons as S 2-?
a) O2-
b) Si
c) S2-
d) Ar
3. Given the Lewis electron-dot diagram:
Which electrons are represented by all of the dots?
a) the carbon valence electrons, only
b) the hydrogen valence electrons, only
c) the carbon and hydrogen valence electrons
d) all of the carbon and hydrogen electrons
4. The elements Li and F combine to form an ionic compound. The electron configurations in this compound
are the same as the electron configurations of atoms in Group
a) 1
b) 14
c) 17
d) 18
5. Which term indicates how strongly an atom attracts the electrons in a chemical bond?
a) alkalinity
b) atomic mass
c) electronegativity
d) activation energy
6. Which element has atoms with the greatest attraction for electrons in a chemical bond?
a) beryllium
b) fluorine
c) lithium
d) oxygen
7. Which pair of elements below will form a compound with the greatest ionic character?
a) Pb and F
b) Ca and O
c) Na and Cl
d) Cs and N
8. Which substance contains bonds that involved the transfer of electrons from one atom to another?
a) CO2
b) NH3
c) KBr
d) Cl2
9. Compared to a calcium atom, the calcium ion Ca2+ has
a) more protons
b) fewer protons
c) more electrons
d) fewer electrons
10. Which statement best describes the substance that results when electrons are transferred from a
metal to a nonmetal?
a) It contains ionic bonds and has a low melting point.
b) It contains ionic bonds and has a high melting point.
c) It contains covalent bonds and has a low melting point.
d) It contains covalent bonds and has a high melting point.
11. Conductivity in a metal results from
a) high electronegativity
b) high ionization energy
c) highly mobile protons in the nucleus
d) highly mobile electrons in the valence shell
12. Which formula represents a nonpolar molecule with polar covalent bonds?
a) H2O
b) CCl4
c) NH3
d) H2
13. Which forula represents a polar molecule?
a) H2
b) H2O
c) CO2
d) CCl4
14. Which formulas represent two polar molecules?
a) CO2 and HCl
b) CO2 and CH4
c) H2O and HCl
Unit 6: Naming Formulas / Stoichiometry
1. Which substance has the greatest molecular mass?
a) H2O2
b) NO
c) CF4
d) I2
d) H2O and CH4
2. What is the empirical formula of C3H6?
a) CH
b) CH2
c) CH3
d) CH6
3. Which formula is correct for ammonium sulfate?
a) NH4SO4
b) (NH4)2SO4
c) NH4(SO4)2
d) (NH)3(SO4)2
4. Which equation shows conservation of atoms?
a) H2 + O2  H2O
b) H2 + O2  2 H2O
c) 2 H2 + O2  2 H2O
d) 2 H2 + 2 O2 2 H2O
5. Which formula is both a molecular and an empirical formula?
a) C6H12O6
b) C3H8O
c) C2H4O2
6. The gram-formula mass of NO2 is defined as the mass of
a) one mole of NO2
b) one molecule of NO2
c) two moles of NO
d) two molecules of NO
d) C4H8