Y9 Chemistry Flashcards
Atomic Structure Revision
How many elements in the periodic table?
118
Elements split into what 2 groups
Metals and Non-metals
Atoms are…
The smallest indivisable particle of an element.
Atoms are made of how many parts?
3 subatomic particles
About subatomic particle P…
Protons:
Charge = +1
Mass = 1
Where = Nucleus
About subatomic particle N…
Neutrons:
Charge = 0
Mass = 1
Where = Nucleus
About subatomic particle E…
Electrons:
Charge = -1
Mass = 0.0005
Where = Shell
Chemical Symbol - Meanings
7
Li
Lithium
3
MASS NUMBER
(Number of Protons + Neutrons)
Atomic Symbol
Name of Atom
ATOMIC NUMBER
(Number of Protons)
How to know how many PROTONS in an atom?
Atomic Number
How to know how many NEUTRONS in an atom?
Mass Number - Atomic Number
How to know how many ELECTRONS in an atom?
IF AN ATOM…
Same amount as Protons (Atomic Number)
How do you show how many atoms electrons per shell without drawing them
ELECTRON CONFIGURATION
Shows electron configuration
e.g. (Shell 1, Shell 2, Shell 3)
( 2 ,8 ,3 ) - Al
How do atoms like their outer shells?
Atoms prefer full outer shells
They can achieve this by losing or gaining electrons
What is an Ion?
An Ion is an atom that has lost or gained electrons
What are Isotopes?
Isotopes are forms of an element that have the same number of protons and electrons but a different number of neutrons.
Isotopes of an element can be easily identified because their atomic number is the same but their mass numbers are different
An isotope is named after the element and the mass number of its atoms.
❌ - CHANGE ✅ - SaMe
MASS NUMBER ❌
symbol ✅
Name ✅
AtOmIc NuMbEr ✅
Where did the idea of the atom come from?
The concept of the atom originated in Ancient Greece
In Greek ‘atomas’ means indivisible
1st Periodic Table
John Dalton
19th Century
Ordered by weight
2nd Periodic Table
John Newlands
1864
Ordered by Mass
Law of Octaves
Didn’t leave gaps
3rd Periodic Table
Modern
Dmitri Mendeleev
1869
Arranged by atomic number
Left gaps
Predicted properties of 5 elements, 3 were discovered and he was right
Discovery of Noble Gases proved him right
Distillation
A technique used to separate liquid from a mixture
Chromatography
A technique to separate dissolved solids from each other
Vertical columns of the Periodic Table
Groups
Horizontal rows of the Periodic Table
Periods
Elements touching the Zigzag are classified as…
Metalloids
