more Flashcards
What increases as it goes down group 1?
reactivity
What types of properties do transition metals have?
typical metal properties (eg. malleable, ductile, good conductors of heat and electricity, shiny)
What are transition metals often used as in a reaction?
catalysts
What 2 things can transition metals often form?
ions, coloured compounds
What are 3 properties of alkali metals?
soft, reactive, low melting point
What does bromine form?
dark red vapour
What does iodine form?
shiny, black crystals
What does chlorine form?
green
lithium+iodine→
lithium iodide
potassium+bromine→
potassium bromide
What does metal oxide form?
A tarnish
When sodium reacts with water, what does it do?
floats as a molten ball of metal
What does potassium do when it reacts with water?
floats, making a lilac foam
What happens to lithium when it reacts with water?
floats, forming LiOH
What gas is made when an alkali metal reacts with water?
hydrogen
What do noble gases all form at room temperature?
colourless gases
What is common between noble gases?
They are all very unreactive.
Atoms with incomplete _____ are unstable.
outer electron shells
How do atoms obtain a full outer electron shell and become stable?
by either gaining or losing electrons
An unequal number of protons and electrons makes what?
ions
An atom that loses electrons is a ________ ion.
positive
An atom that gains an electron is a ________ ion.
negative
Metal atoms form positive/negative ions.
positive
Non-metal atoms form positive/negative ions.
negative
Who noticed sets of three elements with similar properties?
Dobereiner
When were Dobereiner triads discovered?
1829
Who placed elements in order of atomic weight?
Newlands
When was the ‘law of octaves’ discovered?
1865
Who put the elements in order of atomic weight but swapped some around?
Dmitri Mendeleev
When were the elements put in order of atomic weight with some swapped around?
1869
Who arranged the elements in order of atomic weights?
John Dalton
When were elements arranged in order of atomic weights?
1808-1810
Who suggested that each element contained identical atoms?
John Dalton
Who reintroduced the idea that everything was made of atoms?
John Dalton
Who said that atoms are solid spheres of matter which can not be split?
John Dalton
Who discovered electrons?
JJ Thomson
Who suggested that an atom is mostly empty space?
Rutherford
Who suggested that an atom is a positively charged sphere with negative electrons distributed throughout it?
JJ Thomson
Who made the plum pudding model?
JJ Thomson
Who suggested that an atom has most of its mass in a tiny central nucleus?
Rutherford
Who suggested that electrons orbit the nucleus at specific distances?
Neils Bohr
