pre ap chem review
f electromagnetic radiation A has a lower frequency than electromagnetic radiation B, then compared to B, the wavelength of A is
longer
The compressibility of solids is generally
lower than the compressibility of liquids and gases
An example of an extensive physical property is
mass
Two features that distinguish matter are
mass and volume
Atoms of the same element can differ in
mass number
The total number of protons and neutrons in the nucleus of an atom is its
mass number
Isotopes are atoms of the same element that have different
masses
A physical property may be investigated by
melting ice
The elements that border the zigzag line in the periodic table are
metaloids
Physical means can be used to separate
mixtures
Compared with the particles in a gas, the particles in a liquid
move around less
The average atomic mass of an element is the average of the atomic masses of its
naturally occurring isotopes
A student making a serial dilution of hydrochloric acid spills a small amount of the acid on the lab table. Which of the following should the student do first?
notify his/her lab partner and tell the teacher
The periodic law states that the physical and chemical properties of elements are periodic functions of their
numbers
Mendeleev's table was called periodic because the properties of the elements
occurred at repeated intervals called periods
If the s and p orbitals of the highest main energy level of an atom are filled with electrons, the atom has a(n)
octet
The electron configurations of the noble gases from neon to radon in the periodic table end with filled
p orbitals
A horizontal row of the periodic table is usually referred to as a
period
Mendeleev is credited with developing the first successful
periodic table
Using the same balance, a chemist obtained the values 5.224 g, 5.235 g, and 5.25 g for the mass of a sample. These measurements have
poor precision
These values were obtained as the mass of products from the same reaction: 8.83 g; 8.84 g; 8.82 g. The known mass of products from that reaction is 8.60 g. The values are
precise
A chemist who frequently carries out a complex experiment is likely to have high
precision
Elements in a group or column in the periodic table can be expected to have similar
properies
The atomic number of oxygen, 8, indicates that there are eight
protons in the nucleus of an oxygen atom
One chemical property of matter is
reactivity
The average atomic mass of an element depends on both the masses of its isotopes and each isotope's
relative abundance
Which of the following observations is qualitative (observational data)?
salt deposits form from an evaporated liquid
Compared with nonmetals, the number of valence electrons in metals is generally
smaller
The state of matter in which particles are rigidly held in fixed positions is the
solid state
The substances that are chemically bound together are
the elements that compose water
Which of the following observations is quantitative (numerical data)?
the liquid boils at 100°C
Isotopes of each element differ in
the number of neutrons in the nucleus
Which of the following is NOT part of Dalton's atomic theory?
the number of protons in an atom is its atomic number=
What causes the high density of solids?
the particles are packed closely together
A line spectrum is produced when an electron moves from one energy leve
to a lower energy level
The attractive forces in a liquid are
too weak to hold the particles in fixed positions
Which is NOT a property of metals?
unreactivity
Under ordinary conditions of temperature and pressure, the particles in a gas are
very far from each other
Particles within a solid
vibrate weakly about fixed positions
A list of pure substances could include
vitamin C (abscorbic acid)
The distance between two successive peaks on a wave is its
wavelength
In Rutherford's experiments, positively charged particles
were used to bombard thin metal foil
100. Simplify the following expression. Express the answer in scientific notation and to the correct number of significant figures.
6.6 x 104
The number of electrons in the highest energy level of the argon atom (atomic number 18) is
8
The homogeneous mixture in the illustration above is in container
A
Which statement describes a physical change?
A sculptor casts a statue in molten bronze and allows it to harden
The state of matter in which a material has a definite volume but no definite shape is the
liquid state
Which is an acceptable way to protect your eyes in the chemistry laboratory?
Only by wearing chemical safety goggles
Which are the chemical symbols for lead, oxygen, and silver, in that order?
Pb, O, Ag
A sheet of paper is torn into several small pieces. Which type of change has happened to the paper?
Physical change only
Which of these entries in the table refers to a chemical property of methanol?
Products Products of combustion
In Group 2A elements, the valence electrons are in sublevel
S
What is the electron configuration for nitrogen, atomic number 7?
1s2 2s2 2p3
The electron notation for aluminum (atomic number 13) is
1s2 2s2 2p6 3s2 3p1
Which of the following is a physical property of a substance in the liquid state?
definite volume
Experiments with cathode rays led to the discovery of the
electron
Group ____ in the periodic table contains only metals.
2A
The electron configuration of aluminum, atomic number 13, is [Ne] 3s23pl. Aluminum is in Period
3
The electron configuration of nitrogen is 1s22s22p3. How many more electrons does nitrogen need to satisfy the octet rule?
3
What is the number of significant figures in the measurement 5.00 cubic meters?
3
A sample of element X contains 90 percent35X atoms, 8.0 percent 37X atoms, and 2.0 percent 38X atoms. The average atomic mass is closest to-
35 amu
if 75.0% of the atoms of an element each have a mass of 35.0amu, and 25.0% of the atoms each have a mass of 37.0 amu, what is the average atomic mass of the element?
35.5 amu
In the electron configuration for scandium (atomic number 21), what is the notation for the three highest-energy electrons?
3d14s2
What is the number 0.0513 expressed in scientific notation?
5.13x 10-2
Which of these observations or values represents an extensive property of the material?
500 cm
The electron configuration for the carbon atom (C) is 1s2 2s2 2p2. The atomic number of carbon is
6
Why do all samples of a given substance have the same intensive properties?
All the samples have the same chemical composition.
How are compounds different from elements?
Compounds can be broken apart by chemical means into simpler substances, but elements cannot
A student observes a crack in a test tube that will be used for a lab. What should the student do with the cracked test tube?
Dispose of the cracked test tube in a designated container
Which groups in the main group have lower electronegativity than d-block elements?
Groups 1 and 2
Which two categories are used to classify properties of matter?
Intensive and extensive
Is the freezing of mercury a reversible or irreversible physical change? Why?
It is reversible because solid mercury can be melted to form liquid mercury again.
Upon completion of a laboratory investigation, where should students return the materials?
Materials should be returned to the teacher designated location
The element with electron configuration 1s2 2s2 2p6 3s2 3p2 is
Si (Z= 14)
What are the three main states of matter?
Solid, liquid, gas
What procedure should be used to put out a fire at a lab station that is fueled by flammable liquids?
Spray with a carbon dioxide or drychemical
A chemist mixes liquid Substance X and solid Substance Y in a beaker, then stirs the mixture vigorously. Which observation or measurement would provide the strongest evidence that the two substances have undergone a physical change, but not a chemical change?
The mixture can be separated into two substances, one with the same melting point as Substance X and the other with the same melting point as Substance Y.
A measurement that closely agrees with accepted values is said to be
accurate
A measurement is said to have good precision if it
agrees closely with other measurements of the same quantity
The group of soft, silvery active metals, all of which have one electron in an s orbital, is known as the
alkali metals
The most characteristic property of the noble gases is that they
are largely unreactive
Which concept in Dalton's atomic theory has been modified?
atoms cannot be divided
Poor precision in scientific measurement may arise from
both human error and the limitations of the measuring instrument
A positive ion is known as a(n)
cation
The electrostatic attraction between positively charged nuclei and negatively charged electrons permits two atoms to be held together by a(n)
chemical bond
Precision pertains to all of the following EXCEPT
closeness of a measurement to an accepted value
Which of the following is an intensive physical property?
colour
The principles of atomic theory recognized today were conceived by
dalton
The change of an atom from an excited state to the ground state always requires
emission of electromagnetic radiation
Which of the following is a physical change?
evaporation
One of the wave properties of electromagnetic radiation, such as light, is
frequency
Across a period in the periodic table, atomic radii
gradually decrease
If electrons in an atom have the lowest possible energies, the atom is in the
ground state
Hydrogen is placed separately from other elements in the periodic table because it
has many unique properties
In the alkaline-earth group,atoms with the smallest radii
have the highest ionization energies.
Chemical properties
include changes that alter the identity of a substance
Compared with gases, solids are
incompressible
As the atomic number increases, the number of electrons in an atom
increases
Helium-4 and helium-3 are
isotopes
Matter includes all of the following EXCEPT
light
