A Substantially Equal Periodic Payment plan allows individuals with qualified retirement plans to withdraw funds before the age of 59 1/2 without penalties.

A periodic payment plan is a type of investment plan that allows an investor to invest in shares of a mutual fund by making small periodic payments.

A periodic payment note, often referred to as an installment note or contract, is a note that provides for periodic payments during the life of the note until the loan amount has been paid in full.

In this periodic table of elements quiz, you have 10 minutes to name as many elements as you can, given only their symbol, atomic weight and the broad group they live in.

This video excerpt from NOVA's "Hunting the Elements" looks at how early chemists developed the periodic table.

A new version of the periodic table of elements has predicted hundreds of highly charged ions that could be used to create the next generation of optical atomic clocks.

Classroom and educational resources to engage students ages 15–18 with the periodic table.

A periodic penalty payment is a period during which a staff member, who is not at his place of work, must be able to take action if his administration so requests.

The asteroid named 33 Polyhymnia is so dense that researchers theorize that it may be made up of elements not contained on the periodic table.

The theory of evolution is fundamental to biology — and the periodic table is literally elemental to our understanding of the world.

Substantially equal periodic payments (SEPP) are based on your life expectancy. There are three IRS-approved methods that can be used to calculate your substantially equal payments, outlined below.