A chemical can be defined as
a. any substance that has a definite composition.
b. any substance that is not alive.
c. an unnatural additive placed in food.
a. any substance that has a definite composition.
100
What is the SI base unit for temperature?
a. liter
b. second
c. Kelvin
kelvin
100
According to the law of conservation of mass, when sodium, hydrogen, and oxygen react to
form a compound, the mass of the compound is ____ the sum of the masses of the individual
elements.
a. less than
b. equal to
c. greater than
equal to
100
The frequency of electromagnetic radiation is measured in waves/second, or
a. Joules (J)
b. Quanta (Q)
c. Hertz (1/s or Hz)
Hertz (1/s or Hz)
100
Mendeleev left empty spaces in his periodic table and predicted the existence of three elements
and their
a. radioactivity.
b. atomic numbers.
c. properties.
properties.
200
Matter includes all of the following except
a. water vapor.
b. smoke
c. lightt
c. light
200
The SI base units for length and time are
a. meter and second.
b. centimeter and second.
c. meter and hour.
meter and second.
200
Thomson's experiments led him to conclude that atoms contain very small particles with:
a. no charge (neutrons)
b. a positive charge (protons)
c. a negative charge (electrons)
negative (electrons)
200
For an electron in an atom to change from the ground state to an excited state,
a. energy must be absorbed.
b. radiation must be emitted.
c. the electron must make a transition from a higher to a lower energy level.
energy must be absorbed.
200
Elements in a group or column in the periodic table can be expected to have similar
a. properties.
b. atomic masses.
c. atomic numbers.
properties
300
4. A physical change occurs when a
a. glue gun melts a glue stick.
b. silver bowl tarnishes.
c. Wood burning
a. glue gun melts a glue stick.
300
The symbol mm represents
a. micrometer.
b. millimeter.
c. meter.
millimeter
300
Which part of an atom has the smallest mass?
a. nucleus
b. electron
c. neutron
electron
300
The electron in a hydrogen atom has its lowest total energy when the electron is in its
a. ground state.
b. neutral state.
c. quantum state.
ground state
300
A horizontal row in the periodic table is called a(n)
a. group.
b. family.
c. period.
period
400
The liquid state of matter can be described as
a. Don’t pick this answer. It is wrong
b. having a definite volume but not a definite shape.
c. having definite shape and definite volume.
b. having a definite volume but not a definite shape.
400
12. The amount of matter in a substance is:
a. density.
b. weight.
c. mass.
mass
400
Isotopes of the same atom have a different number of
a. protons
b. neutrons
c. electrons.
neutrons
400
During radioactive decay, the nucleus disintegrates into
a. a heavier and less stable nucleus.
b. a lighter and more stable nucleus.
c. a heavier and more stable nucleus.
lighter and more stable nucleus
400
How many valence electrons does bromine have?
a. 35
b. 18
c. 7
7
500
If a mixture is uniform in composition, it is said to be
a. a compound.
b. homogeneous.
c. chemically bonded.
b. homogeneous
500
What do you need to determine the density of a material?
a. mass and weight
b. volume and concentration
c. Mass and volume
mass and volume
500
Which describes particles or electromagnetic radiation emitted from the nucleus during
radioactive decay?
a. nuclear radiation
b. daughter nuclides
c. transmutation
nuclear radiation
500
Beta particles are
a. helium nuclei.
b. neutrons.
c. electrons.
electrons
500
In nature, the alkali metals occur as
a. compounds.
b. elements.
c. gases.