Chapter 1
Classify each statement as an observation, a law, or a theory.
a. Chlorine is a highly reactive gas.
b. If elements are listed in order of increasing mass of their atoms, their chemical reactivity follows a repeating pattern.
c. Neon is an inert (or nonreactive) gas.
d. The reactivity of elements depends on the arrangement of their electrons.
a. Observation
b. Law
c. Observation
d. Theory
True or false: For an atom to be neutral, it must have more neutrons than protons or electrons.
False
Define an Ionic Bond
- Between a metal and nonmetal
- Transfer of electrons
Write the formula for the ionic compound that forms between Aluminum and Oxygen
Al2O3
Convert 87.9 x 10-7 cm to km
8.79 x 10-11 km
Which of the following statements about pure substances is FALSE?
a. Made of a single type of atom/molecule
b. Composition is always the same
c. Made of multiple substances that appear to be one
d. Characteristics are always the same
C
Define isotope. Define ion.
Isotopes are atoms with the same number of protons but different numbers of neutrons (different weight). Ions are atoms with the same number of protons but different numbers of electrons (charge).
Define a covalent bond
- Between two nonmetals
- Sharing of electrons
Write the formula for the compound that forms between Calcium and Nitrite
Ca(NO2)2
An ibuprofen suspension for infants contains 100 mg/5.0 mL suspension. The recommended dose is 10 mg/kg body weight. How many mL of this suspension should be given to an infant weighing 18 lb? (Assume two significant figures.) (1 kg = 2.205 lb)
4.1 mL
Classify each of the following as a physical or chemical change
a. Evaporation of rubbing alcohol
b. Burning of oil
c. Bleaching of hair with hydrogen peroxide
d. Frost formation on a cold night
a. Physical
b. Chemical
c. Chemical
d. Physical
Determine the number of protons and neutrons in the isotope shown.
82 protons, 126 neutrons
Identify the following compound as either ionic or molecular:
CO2
Molecular
Name the following compound:
BrF5
Bromine Pentaflouride
Magnesium has three naturally occurring isotopes with the masses and natural abundances shown in the table. Calculate the atomic mass of magnesium in amu.
24.31 amu
Which law states that energy cannot be created or destroyed?
Law of Conservation of Energy
Determine the number of protons and electrons in Cr3+
24 protons, 21 electrons
Identify the following compound as either ionic or molecular:
PtO2
Ionic
Name the following compound:
H2SO4
Sulfuric acid
Calculate the number of atoms in a 2.26 g sample of Hg.
6.79 x 1021 Hg atoms
How many significant figures are in 1.563300 × 1011 m?
7
Provide and example of an alkali metal, alkaline earth metal, halogen, transition metal, and noble gas.
Alkali metal - Column 1A
Alkaline earth metal - Column 2A
Transition metal - Columns 3-12
Halogen - Column 7A
Noble gas - Column 8A
Identify the following compound as either ionic or molecular:
CF2Cl2
Molecular
Name the following compound:
Pb3(PO4)4
Lead (IV) Phosphate
Calculate the number of atoms in a 1.87 g sample of Bi.
5.39 x 1021 Bi atoms