4.1 Flashcards
Which elements on the periodic table have stable nuclei?
elements up to 19
What makes a stable nuclei stable?
forces of attraction and repulsion are balanced
Hoe does a unstable nucleus become more stable?
emit radiation
What is radiation?
particles of energy from unstable nuclei
radioisotopes
isotopes that emit radiation
transmutation
change in number of protons in nucleus
which elements are artificial?
elements 93+
what happens when an atom is emitting radiation? (nucleus energy level)
unstable nuclei becomes stable by forming a lower energy nucleus
Types of radiation
alpha, beta, positron, gamma
alpha particle
particles, mass#, atomic #, charge
identical to helium, 2 protons, 2 neutrons, mass #4, atomic # 2, charge 2+
beta particle
mass#, charge
high energy electron, mass#0, charge 1-,
positron
charge, mass#
charge 1+, mass 0
gamma ray
mass#, atomic #
mass# 0,
atomic # 0
what may happen to an electron when radiation strikes it? what is formed?
what is this process called?
electrons may be knocked away,
forming unstable ions
ionization radiation
what happens when ionizing radiation passes the human body?
what is formed?
why is it dangerous?
it may interact with water molecules removing electrons forming H20+
H20+ can cause undesirable chemical reactions
which cells are most sensitive to ionization radiation?
cells that undergo rapid division
bone marrow, skin, reproductive organs, cells of growing children, cancer
Protection from radiation: Alpha particles
paper, clothing, skin
Protection from radiation: Beta particles
heavy clothes
eg. lab coat, gloves
Protection from radiation: gamma ray
lead shield, thick concrete walls
how can you protect yourself from radiation?
limit your time with it (less exposure) greater distance (lower intensity)
most common source of alpha particle
radium 226
most common source of beta particles
carbon 14
most common source of gamma rays
technetium-99m
