Periodic Table and Periodic Law Flashcards
How many elements were in the periodic table in 330 BC?
4 elements
How many elements were in the periodic table in 1800
31 elements
How many elements were in the periodic table in 1865?
63 elements
What law did Johann Dobereiner come up with?
the Law of Triads
What is the Law of Triads?
it creates groups of three elements with similar properties. For example, lithium, potassium and sodium all had similar atomic masses
What law did John Alexander Newlands come up with?
Law of Octaves
How did John Alexander Newlands organize the periodic table?
arranged all known elements in order of atomic mass and began to group elements into families
What is the law of octaves?
observed that every eigth element had similar physical and chemical properties
Who is credited as the Father of the Periodic Table?
Dimitri Mendeleev
How did Dimitri Mendeleev organize the periodic table?
organized elements by atomic masses that were arranged periodically with elements of similar properties under each other
What did Henry Moseley do in the periodic table?
determied the atomic number of each of the elements and midified the periodic law
What is the modern periodic law?
- The modern periodic table organizes elements based on their atomic number
- the chemical and physical properties of the elements repeat in a regular, periodic pattern when they are arranged according to their atomic number
what are the properties of metals?
- they conduct heat and electricity
- ductile and amlleable
- shiny, often silvery-grey in colour
- solid and room temperature, except mercury
Describe Hydrogen within the periodic table
- a class of it’s own
- sometimes behaves like an alkali metal
sometimes behaves like a halogen - sometimes behaviours in its own unique way
What are the properties of nonmetals?
- poor conductors of heat and electricity
- usually solid or gas at room temperature (usually bromine is a liquid at room temperature)
- brittle
- dull
