Chemistry exam
The compressibility of solids is generally
lower than the compressibility of liquids and gases
An example of an extensive physical property is
mass
the total number of protons and neutrons in the nucleus of an atom is its
mass number
Two features that distinguish matter are
mass/volume
A physical property may be investigated by
melting ice
The elements that border the zigzag line in the periodic table are
metalloids
What are the three broad classes of elements
metals, nonmetals, metalloids
Physical means can be used to separate
mixtures
Compared with the particles in a gas, the particles in a liquid
move around less
To what category of elements does an element belong if it is a poor conductor of electricity?
nonmetals
Isotopes are atoms of the same element that have different
number of electrons
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
The melting of candle wax is classified as a physical change because it
produces no new substances
Elements in a group or column in the periodic table can be expected to have similar
properties
Which subatomic particle plays the greatest part in determining the properties of an element?
proton
One chemical property of matter is
reactivity
The average atomic mass of an element depends on both the masses of its Isotopes and each isotopes
relative abundance
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
What are the three main states of matter?
solid, liquid, gas
The substances that are chemically bound together are
the elements that compose water
Across a period in the periodic table, atomic radii
to gradually decrease
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
In Rutherfords experiments, positively charged particles
were used to bombard thin metal foil
Simplify the following. Express the answer in scientific notation and to the correct number of significant figures. (5. 3 X 10^4)+(1.3 x 10^4)
6.6 x 10^8
The number of electrons in the highest energy level of the argon atom (atomic number 18) is
8
Zoe observes water bubbling. She measures the temperature of the water to be 373 k. Is most likely observing a chemical or physical change.
A chemical change because 373k is the boiling point of water.
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
Sodium hydroxide is a very reactive strong base. What is the chemical formula for sodium hydroxide
NaOH
The homogeneous mixture in the illustration above is in the container
NaOH solution
A student making a serial dilution of hydrochloride 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
If the s and p orbitals of the highest main energy level of an atom are filled with electrons, the atom has a(n) (Hint: How many electrons fill an s sub level ? P sub level?)
Octet
Which is an acceptable way to protect yourself eyes in the chemistry laboratory
Only by wearing chemistry safety goggles
Which are the chemical symbols for lead, oxygen, and silver, in that order?
Pb, O, Ag
Which has the larger first ionization energy-magnesium or phosphorus?
Phosphorus has the greater first ionization energy
A sheet of paper is torn into several small pieces. Which type of change has happened to the paper?
Physical change only
The atomic number of oxygen, 8, indicates that's there are eight.
Protons in the nucleus of an oxygen atom
In group 2A elements, the valence electrons are in sub level
S
Which of the following observations is qualitative?
Salt deposits form from an evaporated liquid
What is the electron configuration for nitrogen, atomic number 7?
1s^2 2s^2 2p^3
The electron notation for aluminum (atomic number 13) is
1s^2 2s^2 2p^6 3s^2 3p^1
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
What is the number of significant figures in the measurement 5.00 cubic meters?
1
Group _ in the periodic contains only metals
2A
The electron configuration of nitrogen is 1s^2 2s^2 2p^3. How many more electrons does nitrogen need to satisfy the octet rule?
3
Which of these observations or values represents an extensive property of the material?
3.01 g/cm^3
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
36.0 amu
A sample of element x contains 90 percent 35^x atoms, and 2.0 percent 38^x atoms. The average atomic mass is closest to
37 amu
What is the number 0.0513 expressed in scientific notation
5.13 x 10^-2
The electron configuration for the carbon atom (c) is 1s^2 2s^2 2p^2
6
What is the chemical formula for aluminum sulfate?
Al^2(SO^4)^3
The group of soft, silvery active metals, all of which have one electron In an s orbital, is known as the
Alkali metals
What information is often included in a periodic table?
All of the above
Why do all samples of a given substance have the same intensive properties?
All the samples have the same mass or volume
What is the correct name for the compound with the formula NH^4NO^2
Ammonium nitrite
The average atomic mass of an element is the average of the atomic masses of its
Artificial isotopes
What is the chemical formula for the carbon tetrachloride?
CCl4
Atoms of the same element can differ in
Chemical properties
What is the correct name for the compound with the formula CrPO^4
Chromium (11) phosphate
How are compounds different from elements?
Compounds can be broken apart by chemical means into simpler substances, but elements cannot.
The principles of atomic theory recognized today were conceived by
Dalton
From top to bottom within a group of the periodic table, first ionization energy tends to
Decrease
from left to Right across a period of the periodic table, atomic radius tends to
Decrease
A student observed 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
Each period in the periodic table corresponds to a (n)
Energy sub level
Which two words, in order, correctly complete the statement? Two major categories of chemical compounds are _and _.
Ionic and covalent
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.
How many electrons will a calcium (Ca) atom gain or lose in forming an ion?
It will lose 2 electrons
Upon completion of a laboratory investigation, where should students return the materials?
Materials should be returned to the teacher designed location
The element with electron configuration 1s^2 2s^2 2p^6 3s^2 3p^2
Si (Z=14)
What is the name for NaClO3
Sodium chlorate
Using the periodic table. Which element has properties most similar to those of sodium?
Sulfur
Which of the following observations is quantitative?
The liquid boils at 100°C
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.
What causes the high density of solids?
The particles are packed closely together
Isotopes of each element differ in
The total number of electrons
A list of pure substances could include
Vitamin C (ascorbic acid)
A chemical change occurs when
a leaf changes color
The change of an atom from an excited state to the ground state always requires
absorption of energy
The most characteristic property of the noble gases is that they
are largely unreactive
A positive ion is known as a(n)
cation
Which of the following is an intensive physical property?
color
Which of the following is a physical change?
evaporation
If electrons in an atom have the lowest possible energies, the atom is in the
ground state
Which groups in the main group have lower electronegativity than d-block elements?
groups 1 and 2
In the alkaline-earth group, atoms with the smallest radii
have the highest ionization energies
The noble gases include helium, neon, argon, and xenon. What do their electron configurations have in common?
in the highest occupied energy level, the s and p sublevels are completely filled.
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
Which two categories are used to classify properties of matter?
intensive and extensive
Helium-4 and helium-3 are
isotopes
Matter includes all of the following EXCEPT
light