Friday, August 31, 2012

chemistry


chemistry

At 1 atmosphere of pressure, 25.0 grams of a compound at its boiling point is converted to a gas by the addition of 8,180 calories. What is the heat of vaporization for this compound, in calories per gram?

A. 25.0 cal/g
*B. 327 cal/g 
C. 540 cal/g
D. 8,140 cal/g

Which substance can be decomposed chemically?

A. CaO and Ca
B. MgO and Mg
C. CO and Co
*D. CaO and MgO 

The particles of a substance are arranged in a definite shape geometric pattern and are constantly vibrating. This substance can be in 

*A. The solid phase, only 
B. The liquid phase, only
C. Either the liquid or the solid phase
D. Neither the liquid or the solid phase

Thursday, August 30, 2012

chemistry


chemistry

What is the volume occupied by 2.0 moles of Ar(g) at STP?

A. 22.4 L
*B. 44.8 L 
C. 89.6 L
D. 179 L

Which gas is least likely to obey the ideal gas laws at very high temperatures and very low temperatures? 

A. Kr
B. Ne
C. He
*D. Xe 

 A gas at STP has a volume of 1.0 liters. If the pressure is doubled and the temperature remains constant, the new volume of the gas will be 

A. .25 L
B. 2.0 L
*C. .50 L 
D. 4.0 L

Wednesday, August 29, 2012

chemistry


chemistry

A sample of oxygen gas in a closed system has a volume of 200 milliliters at 600 K. If the pressure is held constant and the temperature is lowered to 300 K, the volume of the gas will be

*A. 100 ml 
B. 200 ml
C. 300 ml
D. 400 ml

Which sample of water will have the highest water pressure? 

*A. 10.0 mL at 62° C 
B. 20.0 mL at 52° C
C. 30.0 mL at 42° C
D. 40.0 mL at 32° C

 An assumption of the kinetic energy of gases is that the particles of a gas have 

A. Little attraction for each other and a significant volume
*B. Little attraction for each other and an insignificant volume 
C. Strong attraction for each other and a significant volume
D. Strong attraction for each other and an insignificant volume

chemistry


Answers on next post

A sample of oxygen gas in a closed system has a volume of 200 milliliters at 600 K. If the pressure is held constant and the temperature is lowered to 300 K, the volume of the gas will be

A. 100 ml
B. 200 ml
C. 300 ml
D. 400 ml

Which sample of water will have the highest water pressure? 

A. 10.0 mL at 62° C
B. 20.0 mL at 52° C
C. 30.0 mL at 42° C
D. 40.0 mL at 32° C

 An assumption of the kinetic energy of gases is that the particles of a gas have 

A. Little attraction for each other and a significant volume
B. Little attraction for each other and an insignificant volume
C. Strong attraction for each other and a significant volume
D. Strong attraction for each other and an insignificant volume

Tuesday, August 28, 2012

Chem Physics


chemistry

What is the pressure of a mixture of CO2, SO2 and H20 gases, if each gas has a partial pressure of 250 torr?

A. 250 torr
B. 500 torr
*C. 750 torr 
D. 1,000 torr

A gas sample has a volume of 25.0 milliliters at a pressure of 1.0 atmosphere. If the volume increases to 50.0 milliliters and the temperature remains constant, the new pressure will be 

A. 1.0 atm
B. 2.0 atm
C. .250 atm
*D. .500 atm 

An increase of the temperature of a system at equilibrium favors the 

A. Endothermic reaction and decreases its rate
*B. Endothermic reaction and increases its rate 
C. Exothermic reaction and decreases its rate

chemistry


Answers on next post

What is the pressure of a mixture of CO2, SO2 and H20 gases, if each gas has a partial pressure of 250 torr?

A. 250 torr
B. 500 torr
C. 750 torr
D. 1,000 torr

A gas sample has a volume of 25.0 milliliters at a pressure of 1.0 atmosphere. If the volume increases to 50.0 milliliters and the temperature remains constant, the new pressure will be 

A. 1.0 atm
B. 2.0 atm
C. .250 atm
D. .500 atm

An increase of the temperature of a system at equilibrium favors the 

A. Endothermic reaction and decreases its rate
B. Endothermic reaction and increases its rate
C. Exothermic reaction and decreases its rate
D. Exothermic reaction and increases its rate

Monday, August 27, 2012

physics


physics

What is the energy of a quantum of light having a frequency of 6.0 x 10e14 hertz? 



A. 1.6 x 10e8 

*B. 4.0 x 10e8 

C. 1.3 x 10e8 

D. 5.0 x 10e7 J 



 Experiments performed with light indicate that light exhibits 



A. Particle properties, only

B. Wave properties, only

*C. Both particle and wave properties 

D. Neither particle or wave properties



What is the speed of light in a medium having an absolute index of refraction of 2.3? 



A. .77 x 10e8 

*B. 1.3 x 10e8 

C. 1.5 x 10e8 

D. 2.3 x 10e8 m/s 

physics


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What is the energy of a quantum of light having a frequency of 6.0 x 10e14 hertz? 



A. 1.6 x 10e8 

B. 4.0 x 10e8 

C. 1.3 x 10e8 

D. 5.0 x 10e-7 J 



 Experiments performed with light indicate that light exhibits 



A. Particle properties, only

B. Wave properties, only

C. Both particle and wave properties

D. Neither particle or wave properties



What is the speed of light in a medium having an absolute index of refraction of 2.3? 



A. .77 x 10e8 

B. 1.3 x 10e8 

C. 1.5 x 10e8 

D. 2.3 x 10e8 m/s 

Sunday, August 26, 2012

physics


physics

A diverging (concave) lens can form images that are?

*A. Virtual, only 
B. Inverted, only
C. Either virtual or real
D. Either inverted or erect

 A ray of light strikes a plane mirror at an angle of incidence equal to 35 degrees. The angle between the incidence ray and the reflected ray is ___. 

A. 45 degrees
B. 60 degrees
*C. 70 degrees 
D. 80 degrees
 
Compared to the wavelengths of visible light the wavelengths of UV light are 

*A. Shorter 
B. Longer
C. The Same

physics



Answers on next post

A diverging (concave) lens can form images that are?

A. Virtual, only
B. Inverted, only
C. Either virtual or real
D. Either inverted or erect

 A ray of light strikes a plane mirror at an angle of incidence equal to 35 degrees. The angle between the incidence ray and the reflected ray is ___. 

A. 45 degrees
B. 60 degrees
C. 70 degrees
D. 80 degrees
 
Compared to the wavelengths of visible light the wavelengths of UV light are 

A. Shorter
B. Longer
C. The Same

Saturday, August 25, 2012

chemistry

Which of the following element has the corresponding valence subshell of 3p6? Atomic numbers are listed next to the elements.

A. Sulfur 16
B. Chlorine 17
*C. Argon 18 
D. Potassium 19

 Which of the following element has the corresponding valence subshell of 3s1? Atomic numbers are listed next to the elements. 

A. Neon 10
*B. Sodium 11 
C. Magnesium 12
D. Aluminum 13

 Which of the following element has the corresponding valence subshell of 2p4? Atomic numbers are listed next to the elements. 

A. Nitrogen 7
*B. Oxygen 8 
C. Neon 10
D. Magnesium 12

chemistry


chemistry


Answers on next post

Which of the following element has the corresponding valence subshell of 3p6? Atomic numbers are listed next to the elements.

A. Sulfur 16
B. Chlorine 17
C. Argon 18
D. Potassium 19

 Which of the following element has the corresponding valence subshell of 3s1? Atomic numbers are listed next to the elements. 

A. Neon 10
B. Sodium 11
C. Magnesium 12
D. Aluminum 13

 Which of the following element has the corresponding valence subshell of 2p4? Atomic numbers are listed next to the elements. 

A. Nitrogen 7
B. Oxygen 8
C. Neon 10
D. Magnesium 12

Friday, August 24, 2012

chemistry


chemistry

When alpha particles are used to bombard gold foil, most of the alpha particles pass through undeflected. This result indicates that most of the volume of gold atom consists of

A. Neutrons
B. Protons
C. Deuterons
*D. Unoccupied space


When an alpha particle is emitted by an atom, the atomic number of the atom will

*A. Decrease by 2
B. Increase by 2
C. Decrease by 4
D. Increase by 4


Which of the following element has the corresponding valence subshell of 3p4? Atomic numbers are listed next to the elements.

A. Aluminum 13
B. Silicon 14
*C. Sulfur 16
D. Chlorine 17

chemistry


Answers on next post

When alpha particles are used to bombard gold foil, most of the alpha particles pass through undeflected. This result indicates that most of the volume of gold atom consists of

A. Neutrons
B. Protons
C. Deuterons
D. Unoccupied space

15. When an alpha particle is emitted by an atom, the atomic number of the atom will

A. Decrease by 2
B. Increase by 2
C. Decrease by 4
D. Increase by 4

16. Which of the following element has the corresponding valence subshell of 3p4? Atomic numbers are listed next to the elements.

A. Aluminum 13
B. Silicon 14
C. Sulfur 16
D. Chlorine 17

Thursday, August 23, 2012

chemistry


chemistry

Which atom in the ground state has only one unpaired electron in its valence shell?

*A. Aluminum 
B. Silicon
C. Phosphorus
D. Sulfur

The shape and bonding of a diatomic bromine molecule are best described as 

A. Symmetrical and polar
*B. Symmetrical and nonpolar 
C. Asymmetrical and polar
D. Asymmetrical and nonpolar

What is the oxidation number of sulfur in H2SO4? 

A. 0
B. -2
*C. +6 
D. +4

chemistry


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Which atom in the ground state has only one unpaired electron in its valence shell?

A. Aluminum
B. Silicon
C. Phosphorus
D. Sulfur

The shape and bonding of a diatomic bromine molecule are best described as 

A. Symmetrical and polar
B. Symmetrical and nonpolar
C. Asymmetrical and polar
D. Asymmetrical and nonpolar

What is the oxidation number of sulfur in H2SO4? 

A. 0
B. -2
C. +6
D. +4

Wednesday, August 22, 2012

chemistry


Answers on next post

An atom in an excited state can have an electron configuration of

A. 1s2 2s2 
B. 1s2 2p1 
C. 1s2 2p2 
D. 1s2 2s2 2p5 
E. 1s2 2s2 2p6 

Compared to the charge and mass of a proton an electron has 

A. The same charge and smaller mass
B. The same charge and the same mass
C. The opposite charge and smaller mass
D. The opposite charge and the same mass

 What is the total number of sublevels in the fourth principal energy level? 

A. 1
B. 2
C. 3
D. 4

chemistry


chemistry

An atom in an excited state can have an electron configuration of

A. 1s2 2s2 
*B. 1s2 2p1 
C. 1s2 2p2 
D. 1s2 2s2 2p5 
E. 1s2 2s2 2p6 

Compared to the charge and mass of a proton an electron has 

A. The same charge and smaller mass
B. The same charge and the same mass
*C. The opposite charge and smaller mass 
D. The opposite charge and the same mass

 What is the total number of sublevels in the fourth principal energy level? 

A. 1
B. 2
C. 3
*D. 4 

Tuesday, August 21, 2012

chemistry


chemistry





In which system do molecule-ion attractions exist?

*A. NaCl(aq)
B. NaCl(s)
C. C6H12O6(aq)
D. C6H12O6(s)


 A particle accelerator can increase the kinetic energy of

*A. An alpha particle and a beta particle
B. An alpha particle and a neutron
C. A gamma ray and a beta particle
D. A neutron and a gamma ray


What is the total number of electrons needed to completely fill all of the orbitals in an atom's second principal energy level?


A. 16
B. 2
*C. 8
D. 4

chemistry


Answers on next post 

In which system do molecule-ion attractions exist? 

A. NaCl(aq)
B. NaCl(s)
C. C6H12O6(aq)
D. C6H12O6(s)

 A particle accelerator can increase the kinetic energy of 

A. An alpha particle and a beta particle
B. An alpha particle and a neutron
C. A gamma ray and a beta particle
D. A neutron and a gamma ray

What is the total number of electrons needed to completely fill all of the orbitals in an atom's second principal energy level? 

A. 16
B. 2
C. 8
D. 4

Sunday, August 19, 2012

chemistry


physics


A (P type) semiconductor is formed by adding impurities, which provide extra ____.

A. Electrons
B. Neutrons
C. Photons
*D. Holes 
 A student measures a current of .05 ampere through a P type semiconductor. If the battery connections are reversed, the current through the semiconductor will be? 

A. Less than .05 ampere
*B. Greater than .05 ampere 
C. The same

 What is the approximate bind energy of a helium nucleus that has a mass defect of 5.2 x 10-29 kilogram? 

A. 4.6 x 10+18 
B. 4.6 x 10-15 
*C. 4.7 x 10-12 
D. 4.7 x 10-18

physics



Answers on next post

A (P type) semiconductor is formed by adding impurities, which provide extra ____.



A. Electrons

B. Neutrons

C. Photons

D. Holes



A student measures a current of .05 ampere through a P type semiconductor. If the battery connections are reversed, the current through the semiconductor will be? 



A. Less than .05 ampere

B. Greater than .05 ampere

C. The same



 What is the approximate bind energy of a helium nucleus that has a mass defect of 5.2 x 10-29 kilogram? 



A. 4.6 x 10+18 

B. 4.6 x 10-15 

C. 4.7 x 10-12 

D. 4.7 x 10-18

Friday, August 17, 2012

physics


physics

What is the net static electric charge on a metal sphere having an excess of +3 elementary charges?



A. 4.7 x 10

B. 8.4 x 10

*C. 4.8 x 10

D. 8.7 x 1019 C



A hydrogen atom could have an electron energy level transition from n=2 to n=3 by absorbing a photon having an energy of?



*A. 1.89 eV

B. 2.04 eV

C. 2.25 eV

D. 2.87 eV



Two solid metal blocks are placed in an insulated container. If there is a net flow of heat between the blocks, they must have different?



*A. Initial temperatures

B. Specific Heat values

C. Melting points

D. Heats of fusion

physics



Answers on next post
What is the net static electric charge on a metal sphere having an excess of +3 elementary charges?

A. 4.7 x 10
B. 8.4 x 10
C. 4.8 x 10
D. 8.7 x 1019 C

A hydrogen atom could have an electron energy level transition from n=2 to n=3 by absorbing a photon having an energy of? 

A. 1.89 eV
B. 2.04 eV
C. 2.25 eV
D. 2.87 eV

Two solid metal blocks are placed in an insulated container. If there is a net flow of heat between the blocks, they must have different? 

A. Initial temperatures
B. Specific Heat values
C. Melting points
D. Heats of fusion



Wednesday, August 15, 2012

chemistry


physics


What is the period of a wave, if 20 crests pass an observer in 4 seconds?

A. 80 s
*B. .2 s 
C. 5 s
D. 4 s

Two waves traveling in the same medium interfere to produce a standing wave. What is the phase difference between the 2 waves at a node? 

A. 0 degrees
B. 90 degrees
*C. 180 degrees 
D. 360 degrees

As a pulse travels along a rope, the pulse loses energy and its amplitude 

*A. Decreases 
B. Increases
C. Remains the same

physics


Answers on next post

What is the period of a wave, if 20 crests pass an observer in 4 seconds?

A. 80 s
B. .2 s
C. 5 s
D. 4 s

Two waves traveling in the same medium interfere to produce a standing wave. What is the phase difference between the 2 waves at a node? 

A. 0 degrees
B. 90 degrees
C. 180 degrees
D. 360 degrees

As a pulse travels along a rope, the pulse loses energy and its amplitude 

A. Decreases
B. Increases
C. Remains the same

Monday, August 13, 2012

physics


Which phenomenon can occur with light, but not with sound? 

A. Doppler effect
B. Interference
*C. Polarization 
D. Refraction

The threshold frequency of a photo emissive surface is 7.0 x 1014 hertz. Which electromagnetic radiation, incident upon the surface, will produce the greatest amount of current? 

A. Low intensity infrared radiation
B. High intensity infrared radiation
C. Low intensity UV radiation
*D. High intensity UV radiation 

 A spherical mirror that forms only virtual images has a radius of curvature of .5 meters. The focal length of this mirror is? 

A. -.125 m
*B. -.25 m 
C. 2.5 m
D. 2.75 m

physics


Answers will be on next post

Which phenomenon can occur with light, but not with sound?

A. Doppler effect
B. Interference
C. Polarization
D. Refraction

The threshold frequency of a photo emissive surface is 7.0 x 1014 hertz. Which electromagnetic radiation, incident upon the surface, will produce the greatest amount of current? 

A. Low intensity infrared radiation
B. High intensity infrared radiation
C. Low intensity UV radiation
D. High intensity UV radiation

 A spherical mirror that forms only virtual images has a radius of curvature of .5 meters. The focal length of this mirror is? 

A. -.125 m
B. -.25 m
C. 2.5 m
D. 2.75 m

physics


Sunday, August 12, 2012

physics


physics

Which of the following is the correct formula for focal point calculation?

A. F= I + O
B. 1/F = I x 1/O
C. F = 1 x 1/O
*D. 1/F = 1/I + 1/O

 Which of the following is the correct formula for lens power (P)?

A. P = 1/f + 1/O
*B. P = 1/f
C. P = f x O
D. P = O/f

 The absolute index of refraction for a substance is 2.0 for light having a wavelength of 5.9 x 10-7 meter. In this substance what is the critical angle for light incident on a boundary with air?

A. 25 Degrees
*B. 30 Degrees
C. 35 Degrees
D. 40 Degrees

physics


Answers will be on next post

Which of the following is the correct formula for focal point calculation?

A. F= I + O
B. 1/F = I x 1/O
C. F = 1 x 1/O
D. 1/F = 1/I + 1/O

Which of the following is the correct formula for lens power (P)? 

A. P = 1/f + 1/O
B. P = 1/f
C. P = f x O
D. P = O/f

The absolute index of refraction for a substance is 2.0 for light having a wavelength of 5.9 x 10-7 meter. In this substance what is the critical angle for light incident on a boundary with air? 

A. 25 Degrees
B. 30 Degrees
C. 35 Degrees
D. 40 Degrees

chemistry




Answers on next post 

At 1 atmosphere of pressure, 25.0 grams of a compound at its boiling point is converted to a gas by the addition of 8,180 calories. What is the heat of vaporization for this compound, in calories per gram?

A. 25.0 cal/g
B. 327 cal/g
C. 540 cal/g
D. 8,140 cal/g

Which substance can be decomposed chemically?

A. CaO and Ca
B. MgO and Mg
C. CO and Co
D. CaO and MgO

The particles of a substance are arranged in a definite shape geometric pattern and are constantly vibrating. This substance can be in 

A. The solid phase, only
B. The liquid phase, only
C. Either the liquid or the solid phase
D. Neither the liquid or the solid phase

chemistry


Answers on next post

What is the volume occupied by 2.0 moles of Ar(g) at STP?

A. 22.4 L
B. 44.8 L
C. 89.6 L
D. 179 L

Which gas is least likely to obey the ideal gas laws at very high temperatures and very low temperatures? 

A. Kr
B. Ne
C. He
D. Xe

 A gas at STP has a volume of 1.0 liters. If the pressure is doubled and the temperature remains constant, the new volume of the gas will be 

A. .25 L
B. 2.0 L
C. .50 L
D. 4.0 L

chemistry


Answers on next post

When alpha particles are used to bombard gold foil, most of the alpha particles pass through undeflected. This result indicates that most of the volume of gold atom consists of

A. Neutrons
B. Protons
C. Deuterons
D. Unoccupied space

When an alpha particle is emitted by an atom, the atomic number of the atom will 

A. Decrease by 2
B. Increase by 2
C. Decrease by 4
D. Increase by 4

 Which of the following element has the corresponding valence subshell of 3p4? Atomic numbers are listed next to the elements. 

A. Aluminum 13
B. Silicon 14
C. Sulfur 16
D. Chlorine 17