Chapter 2: Atoms, Ions And Molecules Flashcards
(24 cards)
Dalton’s atomic theory
All elements are composed of atoms
All elements of the same element are identical in size and mass
Each element has different atoms
Atoms are indestructible
Who discovered subatomic particles?
JJ Thompson
Law of multiple proportions
When two elements form two different compounds the masses of b that combine with 1 g of a can be expressed as a ration of whole numbers
Isotopes
Atoms of an element containing the same number of protons but different number of neutrons
Alkali metals
Shiny, soft metals, highly reactive metals
Do not occur naturally as free elements
Alkali metal electron configuration
One outer shell electron, loses one to become a cation and stable
Alkaline earth metals
Harder, denser, stronger and have higher melting points, lower reactivity than group 1
Alkaline metals electron configuration
2 valence electrons
What reacts with water to form hydroxides?
Alkalines except for beryllium
Group 3
Metals, considered to be poor metals due to low melting points and hardness
Group 3 electrons
3 valence electrons
What reacts with oxygen to form oxides
Group 3
What in group 3 is a metalloid
Boron
Group 4
Mix metals, metalloids and nonmetals, large diversity in properties
What forms hydrides with hydrogen, tetrahalides with halogens, and oxides with oxygen
Group 4A
Group 4a electrons
4 valence electrons, carbon is +4 or -4
Group 5A
All solids except nitrogen, mid of metals, non metals and metalloids
Group 5a electrons
5 valence electrons
Group 6a: chalcogens
Form -2ions when reacting with electropositive metals, solid chalcogens are soft and do not conduct heat well
Group 6a electrons
6 valence electrons
Group 7a: halogens
Reactivity decreases down the group as it becomes harder to add an electron
What do halogens form
Diatomic molecules besides astatine
Halogens electrons
7 valence electrons
Group 8a
Odorless, colorless mono atomic gases with low reactivity and rarely form compounds because of full shell
