Periodic table of the elements

Question 1

State the periodic law

Answer 1

PROPERTIES OF ELEMENTS ARE PERIODIC FUNCTIONS OF THEIR ATOMIC MASSES

Question 2

How did the periodic table develop?

Answer 2

• Law of triads (1817) ~ mass based
• Law of octaves (1864) ~ mass based
• Mendeleev (1869) ~ mass and properties
• Modern periodic table (1940)

Question 3

State the families of elements

Answer 3

• Group1: Alkali Metals
• Group2: Alkaline earth metals
• Group 8: Noble gases
• Group 7: Halogens
• Metalloids
• Transition metals
• lanthanides
• actinides