Chapter 1
Which of the following is a branch of natural science?
a. Chemistry
b. History
c. Sociology
d. Economics
a. Chemistry
Which of the following is not a pure substance?
a. element
b. molecule
c. compound
d. mixture
d. Mixture
The kinetic theory helps to explain the differences between _______________.
a. temperatures of objects
b. particles of matter
c. states of matter
c. states of matter
According to Bohr's theory, an electron's path around the nucleus defines its _____________________.
a. electric charge
b. atomic mass
c. energy level
d. speed
c. Energy level
TRUE or FALSE
A control group in an experiment is exposed to the independent variable.
A model in science is best described as:
a. A scaled-down version of reality
b. A mathematical tool for solving equations
c. A representation used to understand a system
d. An untested theory
c. A representation used to understand a system
A physical property of gold is its _________.
a. density
b. reactivity with powerful acids
c. nonflammability
d. None of the above.
a. Density
When a fixed sample of gas increases in temperature, it must also ______________.
a. increase in pressure
b. decrease in pressure
c. increase in volume
d. increase in mass
a. increase in pressure
Molar mass is defined as _____________________.
a. the number of particles in one mole of a substance.
b. the SI base unit that describes the amount of a substance.
c. the amount of a substance necessary to have a positive charge.
d. the mass in grams of one mole of a substance.
d. the mass in grams of one mole of a substance.
How does the density of an object that sinks into a fluid compare to the density of the fluid?
a. The object that sinks is less dense than the fluid.
b. The object that sinks is more dense than the fluid.
c. The object that sinks is as dense as the fluid.
d. The density of the object is not related to the density of the fluid.
b. The object that sinks is more dense than the fluid.
TRUE or FALSE
A hypothesis must always be tested by experiement.
TRUE
An object's volume can be found by dividing its mass by its __________.
a. pressure
b. temperature
c. density
d. weight
c. Density
Charles’s law relates the volume of a gas to its ______.
a. container
b. pressure
c. composition
d. temperature
d. temperature
Fill in the blank!
The chemical properties of an atom are determined by __________, which are located in the atom's outer energy level.
Valence Electrons
Avogrado's number is defined as the number of particles in ______________________.
a. one mole of a substance.
b. one liter of a substance.
c. one gram of a substance.
d. one kilogram of a substance.
a. one mole of a substance.
TRUE or FALSE
Scientific laws explain why events occur.
FALSE
A chemical change occurs whenever ___________.
a. substances are mixed
b. hot objects melt
c. objects change shape
d. new substances form
d. new substances form
Fill in the blank!
Archimedes' principle states that the ___________ on an object in a fluid is equal to the weight of the volume of fluid that the object displaces.
Buoyant Force
Fill in the blank!
Rutherford's gold-foil experiment revealed that an atom's positive charge is concentrated in the atom's ___________.
Nucleus
The different substances in a mixture ___________.
a. keep their properties
b. form new molecules
c. combine chemically
d. cannot be separated
a. keep their properties
Fill in the blank!
Length, mass, time, and temperature are examples of ____________ in the SI system.
Base Units
How many atoms are in a single molecule of Fe2O3?
a. 2
b. 5
c. 3
d. 6
b. 5
Fill in the blank!
Gay-Lussac's law related the pressure of a gas to the _________ of gas.
Temperature
An atom's mass number equals the number of ____________________.
a. protons plus the number of electrons.
b. protons plus the number of neutrons.
c. protons.
d. neutrons.
b. protons plus the number of neutrons.
Fill in the blank!
A tentative explanation or possible solution to a scientific problem is called a(n) ______________.
Hypothesis