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