Chem final
What is the symbol and meaning of the prefix milli-?
m; 10-3
The electron configurations of the noble gases for neon to radon in the periodic table end with filled
p orbitals
The atomic number of oxygen, 8. indicates that there are eight
protons in the nucleus of an oxygen atom
Simplify the following expression. Express the answer in scientific notation and to the correct number of significant figures.
6.6 x 10 4
The number of electrons in the highest energy level of the argon atom (atomic number 18) is
8
What is the volume of a paperback book 21 cm tall, 12 cm wide, and 3.5 cm thick?
8.8 x 10 3 cm3
The homogeneous mixture in the illustration above is in container
A
Zoe observes water bubbling. She measures the temperature of the water to be 373 K. Is she most likely observing a chemical or physical change?
A physical change because 373 K 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
Physical means can be used to separate
Mixtures
Compared with a particles and 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. Whick 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 energy level of an atom are filled with electrons, the atom has a (n) (Hint: How many electrons fill an s sublevel? p sublevel7)
Octet
Which is an acceptable way to protect your eyes in a 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 horizontal row of the periodic table is usually referred to as a
Period
Mendeleev is credited with developing the first successful
Periodic table
A sheet of paper is torn into several small pieces. Which type of change has happened to the paper?
Physical change only
Using the same balance, a chemist obtained the values 5.224 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 is 8.60 g. The values are
Precise
A chemist who frequently carries out a complex experiment is likely to have have
Precision
The table shows some information from a MSDS for methanol. Which of these entries in the table refers to a chemical property of methanol?
Products of combustion
Elements in a group or column in the periodic table can be expected to have similiar
Properties
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
In Group 2A elements, the valence electrons are in in sublevel
S
Which of the following observations is qualitative?
Salt deposits form from an evaporated liquid
The electron notation for aluminum (atomic number 13) is
1s2 2s2 2p2 3x2 3p1
What is the electron configuration for nitrogen, atomic number 7
1x2 2x2 p2
Ultraviolet radiation with a frequency of 1.18 x 10 15 Hz is used to disinfect water. What is the wavelength of this radiation?
2.54 x 10-7 m
Group______ in the period table contains only metals
2A
The electron configuration of nitrogen is 1s2 2s2 2p3. How many electrons does nitrogen need to satisfy the octel rule?
3
What is the number of significant figures in the measurement 5.00 cubic meters?
3
A sample of element X contains 90 percent 35X atoms, 8.0 percent 37X atoms, and 2.0 percent 38X atoms. The average atomic mass is closes to-
35 amu
If 75.0% of the atoms of an element each have a mass of 35.0 amu, 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
What is the energy of a quantum of blue light with a wavelength of 4.60 x 10-7 m
4.3 x 10-19 J
A hydrogen lamp emits several lines in the visible region of the electromagnetic sprectrum. One of these lines has a wavelength of 6.56 x 10-7 m. What is frequency of this radition?
4.57 x 10 14 s-1
What is the number 0.0513 expressed in scientific notation?
5.13 x 10-2
A laser pointer emits light that's a wavelength of 5.32 x 10-7 m. What is the frequency of the light?
5.64 x 10 14 Hz
A chemical engineer evaluates a compound to determine whether it would be a suitable replacement for the coolant in an air conditioner. Properties of the sample are shown in the table. Which of these observations or values represents an extensive property of the material?
500 cm3
The electron configuration for the carbon atom (C) is 1x2 2x2 2p2. The atomic number of carbon is
6
A measurement is said to have good precision it it
Agrees closely with other measurements of the same quanitity.
Why do all samples of a given substance have the same intensive properties?
All the samples have the same chemical composition
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
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
Color
How are compounds different from elements?
Compounds can be broken apart by chemicals means into simpler substances, but elements cannot
The principles of atomic theory recognized today were conceived by
Dalton
Which of the following is a physical property of a substance in the liquid state?
Definite volume
A student observes a crack in a tet tube that will be used for a lab. What should the student do with the cracked test tube?
Dispose of the cracked test tub in a designated container
The elements that border the zigzag line in the periodic table are
Metalloids
Experiments with cathode rays led to the discovery of the
Electron
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
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
Chemical properties
Include changes that alter the identity of a substance
Compared with gas, 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
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
The state of matter in which a material has a definite volume but no definite shape is the
Liquid state
The 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
Upon completion of a laboratory investigation, where should students return the materials?
Material should be returned to the teacher designated location
A physical property may be investigated by
Melting ice
The element with electron configuration 1x2 2x2 2p 3x2 3p2 is
Si (Z=14)
Compared with nonmetals, the number of valence eletrons in metals is generally
Smaller
The state of matter in which principals are rigidly held in fixed positions is the
Solid state
What are the three main states of matter?
Solid, liquid, gas
Which of the following observations is quantitative
The Liquid boils at 100.c
The substances that are chemically bound together are
The elements that compose water
A chemist mixes liquid Substances 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
Isotopes of each element differ in
The number of neutrons in the nucleus
What causes the high density of solids
The particles are packed closely together
Which equal the speed of a wave?
The product of a wavelength and frequency
A line spectrum is produced when an electron moves from one energy level to a higher energy level
To a lower energy level
The attractive forces in a liquid are
Too weak to hold particles in fixed positions
Which is NOT a property of metals
Unreactivity
Under ordinary conditions o temperature and pressure, the particles, in a gas are
Very far from each other
Particles within a solid
Vibrate weakly about fixed positions
How does visible light differ from radio waves, microwaves, and the other components of the electromagnetic spectrum?
Visible light has a different range of frequencies and wavelengths
A list of pure substances could include
Vitamin C (ascorbic acid)
The distance between two successive peaks on a wave is
Wavelength
In Rutherford's experiments, positively charged particles
Were used to bombard thin metal foil
A measurement that closely agrees with accepted values is said to be?
accurate
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
are largely unreactive
Matter includes all of the following EXCEPT
light
