Chapter 25: Nuclear Changes

Thyroid Gland

The ________ is located in your neck and produces chemical compounds called hormones.

Radiation

________ can be used to stop some types of cancerous cells from growing.

Protons

________ and neutrons are packed together tightly in a nucleus.

Radioactive Isotopes

________ can be located by detecting the radiation they emit.

radioisotopes

Some ________ decay to stable atoms in less than a second.

Cloud Chamber

________: used to detect alpha or beta particle radiation.

Gamma Rays

________ cause less damage to biological molecules as they pass through living tissue.

Electroscope

When a(n) ________ is given a negative charge, its leaves repel each other and spread apart.

Tracer

________: When a radioisotope is used to find or keep track of molecules in an organism.

Geiger Counter

________: a device that measures the amount of radiation by producing an electric current when it detects a charged particle.

alpha particles

When ________ collide with molecules in the air, positively charged ions and electrons result.

Nucleus

A(n) ________ that decays is called a radioactive ________.

Nuclear Fission

________: The process of splitting a nucleus into several smaller nuclei.

Strong Force

The ________: causes protons and neutrons to be attracted to each other.

Radioactive Dating

________ also can be used to estimate the ages of rocks.

Transmutation

________: the process of changing one element to another through nuclear decay.

nuclear fusion

For ________ to occur, positively charged nuclei must get close to each other.

cancer cells

Because ________ grow quickly, they are more susceptible to absorbing radiation and being damaged than healthy cells are.

Radioactivity

________: process of nuclear decay.

Nuclear Radiation

________ moving through the air can remove electrons from some molecules in air.

alpha decay

In ________, two protons and two neutrons are lost from the nucleus.

Atoms

________ usually contain the same number of protons as electrons.

Particles of Nuclear Radiation

________ can be detected as they leave trails of bubbles in a bubble chamber.

Fission Reaction

A(n) ________ usually produces several individual neutrons in addition to the smaller nuclei.

unstable nucleus decays

As a(n) ________, a small amount of mass is converted into energy.

Gamma Rays

________: electromagnetic waves with the highest frequencies and the shortest wavelengths in the electromagnetic spectrum.

Alpha Particles

When ________ pass through matter, they exert an electric force on the electrons in atoms in their path.

Cloud Chamber

A(n) ________ is filled with water or ethanol vapor.

Beta Particle

________: The electron emitted from the nucleus.

Background Radiation

Some ________ comes from high- speed nuclei, called cosmic rays, that strike Earths atmosphere.They produce showers of particles, including alpha, beta, and gamma radiation.

Nucleus

The particles in the ________ are attracted to each other by the strong force.

Radioactive Isotope

The ________ carbon- 14 often is used to estimate the ages of plant and animal remains.

Nuclear Fusion

________: two nuclei with small masses combine to form a nucleus of larger mass.

Unstable Nucleus Decays

When a(n) ________, energy is emitted.

Alpha Particles

Some smoke detectors give off ________ that ionize the surrounding air.

Gamma Ray

The ________ produces fewer ions because it has no electric charge.

Alpha Particles

________ can be dangerous if they are released by radioactive atoms inside the human body.

Alpha Particles

________ are the least penetrating form of nuclear radiation.

Alpha Particle

________: made of two protons and two neutrons.

The Strong Force

causes protons and neutrons to be attracted to each other

Radioactivity

process of nuclear decay

Alpha Particle

made of two protons and two neutrons

Transmutation

the process of changing one element to another through nuclear decay

Beta Particle

The electron emitted from the nucleus

Gamma Rays

electromagnetic waves with the highest frequencies and the shortest wavelengths in the electromagnetic spectrum

Half-Life

the amount of time it' takes for half the nuclei in a sample of the isotope to decay

Cloud Chamber

used to detect alpha or beta particle radiation

Bubble Chamber

holds a superheated liquid, which doesnt boil because the pressure in the chamber is high

Geiger Counter

a device that measures the amount of radiation by producing an electric current when it detects a charged particle

Nuclear Fission

The process of splitting a nucleus into several smaller nuclei

Chain Reaction

The series of repeated fission reactions caused by the release of neutrons in each reaction

Critical Mass

the amount of material required so that each fission reaction produces approximately one more fission reaction

Nuclear Fusion

two nuclei with small masses combine to form a nucleus of larger mass

Tracer

When a radioisotope is used to find or keep track of molecules in an organism

Beta Particles

The ________ are absorbed by the surrounding tissues, but the gamma rays penetrate the skin.

Radioactive Iodine

________- 131 accumulates in the thyroid gland and emits gamma rays, which can be detected to form an image of a patients thyroid.

Damage

________ from alpha particles can cause cells not to function properly, leading to illness and disease.

Plates

The ions and electrons move toward charged ________, creating a current in the smoke detector.

Albert Einstein

________ proposed that mass and energy were related in his special theory of relativity.

Background radiation

________ comes from several sources.

Low-Level radiation

It is ________ emitted mainly by naturally occurring radioactive isotopes found in Earths rocks, soils, and atmosphere.

Atoms of an element all

The ________ have the same number of protons in their nuclei.

Radioactive iodine

131 accumulates in the thyroid gland and emits gamma rays, which can be detected to form an image of a patients thyroid