S2 Atomic Theory Flashcards
What is all matter made of?
Atoms
Who discovered atoms?
John Dalton in 1808
Who discovered protons?
Ernest Rutherford in 1919-1920
Who discovered electrons?
JJ Thomson in 1897
Who discovered neutrons?
James Chadwick in 1927
What parts of an atom are found in the nucleus of an atom?
Protons and neutrons
Where are electrons found?
In the shells (energy levels) surrounding the nucleus
What is the number of protons called?
The atomic number
How do you find the number of neutrons in an atom?
Mass number - Atomic number
What is the mass and charge of a proton?
Mass = 1 Charge = positive
What is the mass and charge of an electron?
Mass = 0 Charge = negative
What is the mass and charge of a neutron?
Mass = 1 Charge = Neutral
Who created the periodic table?
Dmitri Mendeleev in 1869
How are the elements organized in the periodic table?
By atomic number
Where do some of the elements name’s originate from?
Greek, Latin, Planets, countries, people who discovered them
What groups of elements are in the periodic table?
Alkali metals, halogens, noble gases, pnictogens, chalcogens
What group number in the periodic table are the alkali metals?
Group 2
What group number in the periodic table are the halogens?
group 7
What group number in the periodic table are the pnictogens?
Group 5
What group number in the periodic table are the noble gases?
Group 8
What group number in the periodic table are the noble gases?
Group 8
What group number in the periodic table are the chalcogens in?
Group 6
What are the properties of metals?
Good conductors of electricity and heat, malleable, high melting point, high density, ductile
Where are metals positioned on the periodic table?
under the stairs
What is a compound?
2 or more elements chemically bonded together
What is a mixture?
2 or more substances that are not chemically bonded
Examples of compounds
When does a compound end with -ide
A 2 element compound
