1143 Questions & Blanks

Question 1

Four properties of cathode rays as demonstrated by J.J.Thomson

Answer 1

They travel in straight lines.
They consist of solid particles.
They carry a negative charge.
Their particles are far smaller than a single atom.

Question 2

Contrast the wave properties of x-ray to ultraviolet

Answer 2

higher frequency
shorter wave length
higher energy
greater penetrating power

Question 3

gamma ray

Answer 3

high speed electromagnetic wave emitted from the nucleus of a radioactive element

Question 4

penetrating power of a gamma particle

Answer 4

greater than alpha or beta

Question 5

cosmic rays

Answer 5

high-speed charged particles, mostly protons, that strike Earth’s atmosphere from outer space

Question 6

precaution with x-rays

Answer 6

limit time of exposure

Question 7

Geiger counter clicks

Answer 7

a radioactive ray produces an ionized path in the gas which completes the circuit

Question 8

superheated liquid

Answer 8

one that has been heated above its boiling point without causing boiling to take place

Question 9

How does radiation damage living tissue?

Answer 9

the rays leave unstable atoms and charged particles which attach themselves to neighboring molecules to produce substances that are foreign to cells

Question 10

What is a model?

Answer 10

a concept that briefly expresses a complex idea

Question 11

The planetary model of the atom as developed by Ernest Rutherford’s work

Answer 11

includes a heavy, positively charged nucleus and light, negatively charged electrons orbiting at relatively great distances

Question 12

the nucleus of an atom

Answer 12

a heavy, positively charged central core

Question 13

alpha particles that traveled through gold foil without changing direction____

Answer 13

struck only electrons. Their mass and velocity allowed them to pass through with their direction unhindered

Question 14

alpha particles that traveled through gold foil but were bent off course _____

Answer 14

passed close enough to an atom’s positively charged nucleus to be deflected by it

Question 15

alpha particles that bounced straight back from the gold foil________

Answer 15

struck the nucleus’ dead center

Question 16

How does the spectroscope help to identify substances objectively?

Answer 16

Each element has its own unique spectral characteristics that identify it exactly. The spectroscope uses these characteristics

Question 17

The photoelectric effect

Answer 17

the emission of electrons caused by light falling upon the surface of certain metals

Question 18

Property of light that determines the number of photons

Answer 18

frequency of light

Question 19

Property of light that determines the energy levels

Answer 19

brightness of light

Question 20

According to Dr. Einstein’s theory, why do photons of red light not produce the photoelectric effect?

Answer 20

they do not have enough energy to free electrons from most metals

Question 21

Five new ideas and discoveries made in physics between 1895 and 1905

Answer 21

discovery of the electron, x-rays, and radioactive elements
development of the quantum theory
explanation of the photoelectric effect

Question 22

Difference between modern and classical physics

Answer 22

Modern physics takes the quantum theory into account. Classical does not.

Question 23

Properties of standard incandescent light

Answer 23

waves out of phase
differing frequencies
direction follows inverse square law

Question 24

Properties of laser light

Answer 24

waves in phase
same frequency
waves travel in the same direction

Question 25

The number of electrons in each atom and their ________ determine an element's chemical properties

Answer 25

Placement in orbitals

Question 26

What are isotopes?

Answer 26

Same number of protons, but different number of neutrons

Question 27

Define radioactivity

Answer 27

The emission of particles or rays from the nucleus of the atom

Question 28

Radioactive decay can make what three fundamental changes in atoms

Answer 28

Change in atomic number Change in atomic mass Change in energy content

Question 29

What is half-life?

Answer 29

Amount of time for a sample of a radioactive elements mass to be halved due to radioactive decay

Question 30

What is a chain reaction

Answer 30

Any process in which the material that starts the reaction is also one of the products

Question 31

The six basic features of a controlled fission nuclear reactor

Answer 31

``` Fuel system Moderator Heat exchanger Cooling system Containment building Control rods ```

Question 32

The importance of critical mass in a fission reaction

Answer 32

It is the smallest mass of fissionable material that will sustain a chain reaction

Question 33

What is fusion

Answer 33

A nuclear reaction in which two lightweight nuclei combine to form a more massive nucleus with the simultaneous release of energy

Question 34

A fusion reaction requires

Answer 34

Intense temperature and pressure

Question 35

A fusion reaction does not require a what does Albert einsteins special theory of relativity conclude?

Answer 35

Energy and mass are interchangeable. Energy and mass are merely different aspects of the same physical phenomenon

Question 36

What is a mass defect?

Answer 36

Difference between mass of an atoms components and the mass of an atoms nucleus

Question 37

Why are the nuclei of some atoms more stable than others?

Answer 37

Some have a greater binding energy per nuclear particle