Arranging The Elements Flashcards
What did he discover?
The elements were periodic
Who discovered the pattern to the elements? When?
Dmitiri Mendeleev-1869
What does periodic mean?
Happened at regular intervals and repeated the pattern every 7 elements
What was he able to predict based on the pattern?
The missing elements
Where was Mendeleev from? What was his job?
A Russian chemist
Who was Henry Mosley?
A British scientist
What did he discover?when.
1914- he determined the number of protons in an atom
What are the number if protons in an atom?
The atomic number
What happened to Mendeleev’s prediction?
All the elements fit when arranged by atomic number
What does the periodic law state?
The repeating chemical and physical properties of elements change periodically with the elements atomic number
What are elements classified as?
Metals, nonmetals, and metalloids
What are they classified according to?
Their properties
What is a characteristic that helps determine what category an element belongs in?
The number of electrons in the pure energy level of an atom
Where are metals found on the periodic table?
On the left of the zig zag line
What do atoms of most metals have?
Few electrons in their outer energy level
What are most metals at room temperature?
Solids
Where are nonmetals found in the periodic table?
On the right of the zig zag line
What do atoms of most nonmetals have?
An almost complete set of electrons in their outer energy level
How many nonmetals are a gas at room temperature?
More than half
What are many properties of nonmetals?
The opposite of metals
What is another name for metalloids?
Semi conductors.
What are metalloids?
The elements that border the zig zag line
What do atoms of metalloids have?
About half a set of electrons in their outer energy level
What do metalloids have properties of?
Metals and nonmetals
