Element's Symbol Writing

Front

What is the proper way to write an element's symbol?

Back

An element's symbol is typically one or two letters, with the first letter capitalized and the second letter, if present, in lowercase.

Front

Who discovered triads?

Back

Johann Dobereiner

Front

What are triads?

Back

Groups of 3 elements that exhibit similar properties

Front

What is periodicity?

Back

A repeated pattern that occurs when you arrange elements with similar properties in order

Front

Who came up with octaves?

Back

John Newlands

Front

What Russian Chemist designed the first periodic table by arranging the elemtns by atomic mass?

Back

Dmitri Mendeleev

Front

What important feature did Dmitri Mendeleev's table have?

Back

He left blank spaces between elements for ones that were unknown then, but he predicted they would be identified in the future. Later, some elements were discovered and it proved that he was right.

Front

What is the original "periodic law" ?

Back

When elements are arranged in order of increasing atomic mass, similar properties recur at regular intervals.

"The physical and chemical properties of elements are a periodic function of their atomic weights."

The original atomic law arranged by atomic mass.

Front

How was the original periodic law revised?

Back

Henry Moseley who discovered that it is better to arrange elements by their atomic NUMBER, not by their mass.

Essentially, the elements are now ordered by their number of protons in the nucleus, not their mass.

The modern periodic law states that chemical properties of elements repeat periodically when arranged according to increasing atomic number.

Front

Who revised Mendeleev's table?

Back

Henry Moseley