Chapter 6

RADIO-ACTIVITY AND CHEMICAL THEORY

Influence upon chemical theory--The periodic system--Basis of the periodic system--Influence of positive nucleus--Determination of the atomic number--Use of X-ray spectra--Changes caused by ray-emission--Atomic weight losses--Lead the end product--Changes of position in the periodic system--Changes from loss of beta particles--Isotopes--Radio-activity in nature--Radio-active products in the earth's crust--Presence in air and soil waters--Cosmical radio-activity 41

INDEX 53

A BRIEF ACCOUNT OF RADIO-ACTIVITY