Exam 5: homework 12

Newton

"add" velocities 2 times the speed of light (c = 3x10^8)

atomic # =

# of protons or electrons

# neutrons =

(atomic mass) - # protons

Beta particle; charge mass

(electron) -1 ≈0

Alpha particle; charge mass

(helium nucleus) +2 4

Gamma particle; charge mass

(photon) 0 0

An electron in the ground state of an atom has an energy of -20.5 eV. What is the energy of the third excited state? Give your answer in eV, and round to 1 decimal place.

-1.3*

An electron in second excited state of an atom has an energy of -8.1 eV. What is the energy of the ground state? Give your answer in eV, and round to 1 decimal place.

-72.9*

A particular nucleus has an atomic number of 13 and an atomic mass of 118 amu. How many neutrons are in the nucleus?

....*

The half-life of phosphorus-32 is approximately 14 days. If you have 8.9 grams of phosphorus-32 today, how many grams will be left after 42 days? Round your answer to 1 decimal place.

....*

neutron; charge mass

0 1

How many protons are in a boron atom?

5*

The critical angle for a light from the bottom of a swimming pool shining upward toward the pool's surface is the angle a. where light is refracted so it just skims the pool surface. b. 43 degrees. c. at which all light is refracted out of the pool. d. 42 degrees. e. at which some light is reflected from the surface.

A where light is refracted so it just skims the pool surface

In beta decay A) an electron is emitted. B) an electron decays into another particle. C) a neutron is emitted. D) a proton is emitted.

A) an electron is emitted.

What is the lowest energy level in an atom called? A. The ground state. B. The floor state. C. The basement state. D. The first state. E. The first excited state.

A. The ground state.*

A beam of light emerges from water into air at an angle. The beam is bent a. away from the normal. b. not at all. c. 48 degrees upward. d. 96 degrees upward. e. towards the normal.

A. away from the normal

In the periodic table, elements in the same ______ have very similar properties. A. column B. row C. nucleus D. ion E. color

A. column*

When a nucleus emits a beta particle, its atomic number A. increases by 1. B. decreases by 1. C. increases by 2. D. decreases by 2. E. none of these

A. increases by 1.*

The Bohr model of the atom is akin to a A. miniature solar system. B. blob of plum pudding, where raisins represent atomic nuclei. C. central heavy ball with lighter balls connected by springs. D. all of these

A. miniature solar system.*

Nuclei which are all isotopes of an element all have the same A. number of protons. B. mass. C. number of nucleons. D. number of neutrons.

A. number of protons.*

The atomic number of an element is the same as the number of its A. protons. B. neutrons. C. nucleons. D. neither of these

A. protons.*

The periodic table is ordered by A. atomic mass. B. atomic number. C. neutron number. D. color of element. E. year of element's discovery.

B. atomic number.*

When a beta particle is ejected from a nucleus, the nucleus then has a greater A. mass. B. charge. C. both of these D. neither of these

B. charge.*

How many electrons are in a neutral oxygen atom? A. 2 B. 4 C. 8 D. 16 E. 32

C. 8*

Most alpha particles fired at a gold foil pass through undeflected because the A. electric field is zero inside the gold. B. gold atoms, unlike most other metal atoms, are relatively far apart. C. atoms of gold, like any others, are mostly empty space. D. net charge of the gold atoms is zero. E. none of these

C. atoms of gold, like any others, are mostly empty space.*

When an alpha particle is ejected from a nucleus, the nucleus then has less A. mass. B. charge. C. both of these D. neither of these

C. both of these*

Which radiation has no electric charge associated with it? A. alpha rays B. beta rays C. gamma rays D. all of these E. none of these

C. gamma rays*

In an electrically neutral atom, the number of protons in the nucleus is balanced by an equal number of A. neutrons. B. quarks. C. orbital electrons. D. all of these E. none of these

C. orbital electrons.*

inverted, reduced, real

Converging lens

Rutherford performed an experiment in which alpha particles were shot at a thin gold foil. About how many of the alpha particles bounced backward from the gold foil? A. 1/10 B. 1/100 C. 1/500 D. 1/1000 E. 1/10,000

D. 1/1000*

The atomic number is the number of ______ in an atom. A. protons B. electrons C. neutrons D. protons or electrons E. protons or neutrons

D. protons or electrons*

upright, reduced, virtual

Diverging lens

E4 =

E1/16

E2 =

E1/4

E3 =

E1/9

Def: atoms whose nuclei have the same # of protons but different # of neutrons

Isotope

Emission of a particle from nucleus

Isotope

particles of light

Photon

the spontaneous release of energy by certain atoms, as these atoms disintegrate.

Radioactivity

Def: the speed of light in a vacuum, measured in any inertial reference frame, always has the same value of c, no matter how fast the source of light and the observer are moving relative to each other.

Speed of Light Postulate

Where is the atomic mass located in the periodic table of elements?

The bottom number

Where is the atomic number located in the periodic table of elements?

The top number

A gamma ray is emitted from a nucleus when

There is a transition between energy levels in the nucleus

A beta particle is emitted from a nucleus when

a neutron is turned into a proton

Beta Decay

a particle auch as the neutron spontaneously transforms into a collections of particles that includes an electron

The law of reflection says that a. the angle of reflection from a mirror equals the angle of incidence. b. waves incident on a mirror are partially reflected. c. all waves incident on a mirror are reflected. d. the angle a ray is reflected from a mirror is random.

a. the angle of reflection from a mirror equals the angle of incidence.

Rutherford

alpha particles at gold foil

An element will decay to an element with lower atomic number in the periodic table if it emits

an alpha particle

An alpha particle will be attracted to a A) positive charge. B) negative charge. C) proton. D) gamma ray.

b. negative charge

The atomic number of an element is the same as the number of its a. electrons b. neutrons c. protons d. energy

c. protons

Alpha particles have an atomic mass equal to A) 1. B) 6. C) 2. D) 4.

d. 4

Which radiation has no electric charge associated with it?

gamma rays

E1 = ?

ground state energy

the theory of special relitivity which deals with a "special" kind of reference frames.

inertial reference frame

Gamma Radiation

involves the emission of energetic electromagnetic radiation from the necleus of an atom, with no change to the # of protons or neutrons in the atom

light is emitted when an electron

makes a transition to a lower energy level

Different isotopes of an element have different numbers of

neutrons

Bohr

orbital

Thomson

plum pudding model

Def: ? the laws of physics are the same in every inertial reference frame

relativity postulate

Maxwell

speed of light is constant (c = 3x10^8)

Alpha Decay

the loss by an atom's nucleus of a large and massive particle composed of two protons and two neutrons.

what happens when electrons go from large orbit to small orbit?

you get energy out