Atomic Structure And The Periodic Table Flashcards
What is chromatography?
Chromatography is the separation of soluble substances
How does it work? - CHROMATOGRAPHY
Your soluble mixtures will be on paper at a level line. The paper is lowered into a solvent, and some dyes spreads up the paper, at different rates.
Why do the mixtures move? - CHROMATOGRAPHY
The different parts of mixtures are attracted to either the paper or the solvent, meaning the mixture separates
How many spots do pure/impure substances make? - CHROMATOGRAPHY
A pure substance creates 1 spot
An impure substance creates more than 1 spot
What were John Dalton’s ideas about atoms? - S+B
That they were tiny, indivisible spheres
Who discovered the electron and what model did this create? - S+B
JJ Thomson, who created the plum pudding model
1909
What experiment did Ernest Rutherford create and what did he find? - S+B
He fired positive alpha particles at gold foil. Most went straight through but some were deflected. This led him to suggest the nuclear model
What is the nuclear model? - S+B
An atom, with its mass concentrated at the positively charged nucleus
Who discovered the electron? - S+B
JJ Thompson
Who discovered neutrons? - S+B
James Chadwick - 1932
What is the atomic number? S+B
The number of protons in an element
What is the mass number of an element? - S+B
The mass number is the number of protons + neutrons in an element
What is an isotope? - S+B
An atom with the same number of protons but a different number of neutrons
What is the symbol for relative atomic mass? - PT
Ar
What problems did John Newlands’ periodic table have? - PT
He didn’t order elements in terms of atomic weight, put multiple elements in the same place, changed positions of elements.
What was good about Mendeleev’s table? - PT
It had spaces left for predicted new elements, decided where elements where misplaced, had elements with similar properties in groups.
Name 4 properties of metals - S+B
Good electric conductors, high melting points, very dense, strong, shiny, ductile
Name 4 properties of non metals - S+B
Low melting point, low density, weak, not ductile, not malleable, poor conductor of electricity
What is Group 0 of the periodic table? + name to properties - PT
The noble gases
Single atoms, very low boiling points, VERY UNREACTIVE
What is group 1 of the PT? + name 2 properties - PT
Alkaline metals
Fairly low melting points
Low densities
Soft (can be cut by a knife)
What happens when Lithium reacts with water? - Reactions
Fizzes slowly
What happens when potassium reacts with water? - Reactions
Burns violently with a lilac flame, often explodes
What do halogens exist as? - S+B
Molecules (diatomic)