U 235 Symbol of Element Mass numbe How do you know the atomic number Find U in

U 235 symbol of element mass numbe how do you know

This preview shows page 18 - 32 out of 149 pages.

U-235Symbol of ElementMass numbeHow do you know the atomic number?Find U in the periodic table. Symbols for IsotopesZ = 92
Image of page 18
Image of page 19
Image of page 20
How are isotopes of the same element alike and different? Alike: 1. Number of protons and electrons 2. Atomic number 3. Chemical properties Different: 1. Number of neutrons 2. Mass Number 3. Atomic mass of the isotopes
Image of page 21
Types of Radiation Isotopes of atoms with unstable nuclei are called radioisotopes . Unstable nuclei emit radiation (release energy) to attain more stable atomic configurations in a process called radioactive decay . The three most common types of radiation are alpha , beta , and gamma . SECTION 2 4.1 Nuclear Radiation Isotope - Atoms of the same element with different number of neutrons .
Image of page 22
Types of Radiation (cont.) SECTION 2 4.1 Nuclear Radiation
Image of page 23
He 4 2 A. Types of Radiation Alpha particle ( ) helium nucleus paper 2+ Beta particle ( -) electron e 0 -1 1- lead Positron ( +) positron e 0 1 1+ Gamma ( ) high-energy photon 0 concrete
Image of page 24
Alpha particles have the same composition as a helium nucleus two protons and two neutrons. Because of the protons, alpha particles have a 2+ charge. Alpha radiation consists of a stream of particles. SECTION 2 4.1 Nuclear Radiation Types of Radiation (cont.)
Image of page 25
Alpha radiation is not very penetrating a single sheet of paper will stop an alpha particle. SECTION 2 4.1 Nuclear Radiation Types of Radiation (cont.)
Image of page 26
Beta particles are very fast-moving electrons emitted when a neutron is converted to a proton. Beta particles have insignificant mass and a 1 charge. SECTION 2 4.1 Nuclear Radiation Types of Radiation (cont.)
Image of page 27
Beta radiation is a stream of fast moving particles with greater penetrating power a thin sheet of foil will stop them. SECTION 2 4.1 Nuclear Radiation Types of Radiation (cont.)
Image of page 28
Gamma rays are high-energy electromagnetic radiation. Gamma rays have no mass or charge. Gamma rays almost always accompany alpha and beta radiation. X rays are a form of high-energy electromagnetic radiation emitted from certain materials in an excited state. (gamma rays) SECTION 2 4.1 Nuclear Radiation Types of Radiation (cont.)
Image of page 29
The ability of radiation to pass through matter is called its penetrating power . Gamma rays are highly penetrating because they have no charge and no mass. SECTION 2 4.1 Nuclear Radiation Types of Radiation (cont.)
Image of page 30
Image of page 31
Image of page 32

You've reached the end of your free preview.

Want to read all 149 pages?