Chemistry 3 Unit 1
How did Newlands and Mendeleev classify elements?
Newlands and Mendeleev classified elements through their atomic weight
This list was arranged in a table so that elements with the same properties are in the same column
Why was the table know as the periodic table?
Known as the periodic table because similar properties occurred at regular intervals
Why was this theory accepted in 1869 than 1863?
Unlike Mendeleev, Newlads did not leave gaps for elements that wasn't discovered yet that had similar properties
What does the modern periodic table display?
Elements are arranged in order of their atomic number. Groups of elements had the same chemical properties because they had the same number of electrons on its outer energy level
What is the trend in reactivity within the groups in the periodic table?
The energy level of the outer electrons:
The more easily electrons are lost
The less easily electrons are gained
What are the elements in group 1 know as?
These elements are known as the alkali metals
What are the properties of group 1
React with non metals to form ionic compounds
React in water releasing hydrogen
Soft solids at room temperature with a low melting/boiling point
What is the Trend the further down we go in the group?
The more reactive
Lower melting/boiling point
Where are transition metals found?
Between groups 2 and 3
Describe the properties of transition metals?
Higher meting/boiling point and higher density that group 1 (except mercury)
Less reactive with water and oxygen
Stronger and harder
They're malleable and ductile and are good conductors
What do transition metals/compounds form?
They form positive ions with various charges
They're catalysts for chemical reactions
What are the elements in group 7 called?
They're known as the halogens and react with metals to form ionic compounds
What are the properties of group 7?
They have a low melting/boiling point and increase going down the group
Less reactive going down the group
The halogens bond covalently with non-metals forming molecules
Chemistry 3 Unit 1
The periodic table