Periodic table Flashcards
(36 cards)
What is an element?
A substance that is made up of only one type of atom.
It cannot be split up further.
What particles does an atom contain?
Protons
Neutrons
Electrons
What is the relative mass, charge and position of a proton
Mass: 1
Charge: +1
Position: Nucleus
What is the relative mass, charge and position of a neutron
Mass: 1
Charge: 0
Position: Nucleus
What is the relative mass, charge and position of a electron?
Mass: 1/1840 (almost nothing)
Charge: -1
Position: Shells orbiting the nucleus
How did John Newlands arrange elements?
In order of atomic mass
Noticed properties seemed to repeat every eighth element - law of octaves.
Why were John Newland’s ideas not accepted at the time?
The order went wrong after calcium e.g. the very unreactive copper was in the group as the highly reactive lithium, sodium and potassium.
How did Dmitri Mendeleev arrange elements?
Put elements in order of increasing atomic mass.
He placed elements with similar chemical properties into veritcal columns called groups.
Left gaps for undiscovered elements.
What was Dmitri Mendeleev able to do with his periodic table?
He was able to predict the properties of undiscovered elements.
What are the differences between Mendeleev’s table and the modern periodic table?
Modern: arranged according to increasing atomic number (number of protons in an atom
Mendeleev: arranged in increasing atomic mass
Modern: has no gaps
Mendeleev: had gaps for undiscovered elements
Modern: has more groups (columns)
Mendeleev: had fewer groups
What is on the left hand side of the periodic table (staircase)
Metals
What is on the right hand side of the periodic table (staircase)
Non-metals
What are some of the elements that touch the divide line?
semi-metals (they have properties of both metals and non-metals)
What are the vertical columns called in the periodic table?
Groups
What are the horizontal rows called in the periodic table?
Periods
What types of symbols represent elements
Letters
Either 1 capital letter or 1 capital letter and 1 small letter
e.g. H - Hydrogen, He - Helium
What other details are on the periodic table?
Top left: Relative atomic mass
Bottom left: Atomic number
What is group 0?
Nobel gases
What is group 1?
Alkali metals
What is group 7?
Halogens
What is group 2?
alkaline earth metals
What can you say about elements in the same group?
They have similar chemical properties
What is a compound made of?
Two or more different elements that are chemically combined.
How is a formula for a compound made up and what does it show?
Symbols and numbers written in subscript.
It shows the elements making up the compound and the number of atoms for each element
