Chapter 9 and 10 UCA Physical Science Homework Q's
The charge on alkali metal ions is
+1
Which of the following statements is not true of all metals
- The are solids at room temperature
The wavelengths in the various spectral series of an element
- are different for each element
The light waves from a laser
- are in step with one another
Electrons
- behave like tiny bar magnets of the SAME strengths
A beam of light whose waves are all in step with one another is said to be
- coherent
Each horizontal row of the periodic table includes elements with chemical characteristics that are, in general
- different
An increase in the voltage applied to an X-ray tube causes an increase in the X-rays'
- energy
The fact that no two electrons in an atom can have the same set of quantum numbers is known as the
- exclusion principle
The sun's spectrum consists of a bright background crossed by dark lines. This suggests that the sun
- is a hot object surrounded by a COOL temperature
The speed of a photon
- is equal to the speed of light
The speed of the wave packet that corresponds to a moving particle is
- less than the speed of light
Photons have
- no charge
A photon is emitted by an atom when one of the atom's electrons
- shifts to a LOWER energy level
When a hydrogen atom is in its lowest energy level,
- the de Broglie wavelength of its electron equals its orbit CIRCUMFERENCE
A proton and an electron have the same de Broglie wavelength
- the electron has the higher speed
The orbital of an electron in an atom is
- the region around the nucleus in which it is most likely to be found
The wave character of a moving golf ball is not observed because
- the wavelength of the matter waves is too short
The idea that light has both wave and particle properties is accepted because
- theory and experiment agree
The charge on halogen ions is
-1
Which of these statements is true for the radiation emitted by all objects?
-The higher an object's temperature, the more radiation it emits
A neon light does not produce
-an ABSORPTION spectrum
In an emission spectral series, the
-excited electrons all return to the same energy level
The photoelectric effect occurs only when the incident light has more than a certain minimum
-frequency
The electron structures of atoms never emit
-gamma rays
When light is directed at a metal surface, the emitted electrons
-have energies that depend upon the FREQUENCY of light
An atom in an excited state usually emits a photon and falls to a state of lower energy m about
10 (to the -8) s
Planck's constant is h= 6.6 x 10 (to the -34) Js. An x-ray has an energy of 6.6 x 10 (to the -15) J. The frequency that corresponds to this energy is
10 (to the 19) Hz
The number of atoms in a molecule of ammonium sulfide (NH4)2S, is
11
The number of oxygen atoms in a molecule of aluminum sulfate Al2(SO4)3 is
12
The missing number is the equation 2Ca(NO3)2 -->2CaO +[ ]NO2 +O2
2
The number of H2O molecules needed to react wit h1 atom of Be to form H2 and Ba(OH) is
2
The number of compounds that carbon and oxygen can form is
2
The number of units of NaOH needed to react with 1 unit of H3PO4 to form Na3PO4 and H2O is
3
Which of the following chemical equations is balanced?
3CUO + 2NH3 -->3Cu + 3H2O +N2
Planck's constant is h= 6.6 x 10 (to the -34) Js. Light of wavelength 5x10(to the -7) m consists of photons whose energy is
4 x10 (to the -19) J
The missing number in the equation 4NH2 + [ ]O2 -->4NO + 6H2O
5
The missing number in the equation 6H3BO3 --> H4B6O11+ [ ]H2O
7
Planck's constant is h= 6.6 x 10 (to the -34) Js and the electron mass is 9.1 x 10(to the -31) kg. The de Broglie wavelength of an electron whose speed is 10(to the 8) m/s is
7.3 x 10(to the -12) m
The name of the compound Ca3N2
Calcium nitride
The scientist who first discovered the relative masses of the atoms of the elements was
Dalton
Potassium forms K+ ions and sulfur form S(2-) ions. The formula of potassium sulfide is
K2S
The ion of the hydroxide group has the symbol
OH-
An atom whose outer electron shell lacks one electron from being filled is
a halogen
In a covalent compound
adjacent atoms share electron pairs
Which of the following is a homogenous mixture?
air
An atom whose outer electron shell is filled is
an inert gas
Organic compounds
are covalent and contain carbon
The inert gases
are in the same group of the periodic table
The metals most difficult to extract from their ores in general
are the MOST active chemically
According to the periodic table, the chemical properties of the elements are periodic functions of their
atomic number
An element that can form an ionic compound with oxygen is
calcium
A free radical is extremely reactive because it
contains an UNPAIRED electron
Table salt, NaCl, consists of
crystals of Na and Cl with IONIC bonds between their IONS
X-rays are
electromagnetic waves of very short wavelength
Each electron shell in an atom contains
electrons with the same principal quantum number n
When atoms join to from a molecule
energy is given off
The rare earth elements are not
extremely rare in the earth's crust
The most active of the following nonmetals is
fluorine
A vertical column in the periodic table is called a
group
A family of elements whose atoms react by picking up electrons is the
halogens
Carbon
has properties intermediate between those of metals and nonmetals
Elements with similar properties (other than atomic mass)
have similar electron configurations
The least active of the following nonmetals is
helium
The most abundant element in the universe is
hydrogen
Which of the following is a compound
ice
In order to increase the rate at which photoelectrons are emitted by a surface on which light is directed, it is necessary to increase the
intensity of light
Which of the following cannot be explained by the quantum theory of light?
interference
A bonding molecular orbital
may consist of any of the above overlaps
Atoms of two different elements
may form no compounds together
The largest number of elements are classed as
metals
Of all the halogens, at room temperature and atmospheric pressure
one is a liquid and the others are gases or solids
A horizontal row in the periodic table is called a
period
The most active of the following metals is
potassium
At room temperature, bromine is a
reddish- brown liquid
The least active of the following metals is
silver
Which of the following is a heterogeneous mixture?
soil
The atomic mass of an element is
the average ATOMIC MASS of its isotopes according to their proportions in nature
The statement that the elements in a given compound are always combined in the same proportions by mass is known as
the law of definite proportions
Each orbital in an atom can be occupied by
two electrons with spins in OPPOSITE directions