Science spiral 2 Flashcards
who is Democritus
he came up with the indivisible particle.
It’s made up of tiny pieces that cannot be broken down.
who is dalton
he came up with the billiard ball model,
atoms are small indivisible particles.
who is thomson
came up with the chocolate chip model.
Theory: negatively charged electrons are found inside a positive charge sphere
who is rutherford
the nuclear model
Theory: atoms are mostly empty space with a positively charged centre
what do elements of the same group have
same number of valance electrons
Which group is each chemical family in and how many valence electrons does each have
alkali- group 1- 1 valance electron
alkaline earth metals group 2- 2 valance electrons
Halogen- group 7/17 - 7 valence electrons
Noble gases- group 8/18- 2/8valence electrons
who is chadwick
model: The planetary model
Theory: nucleus contains neutral particles along with the positively charged particles
who is Bohr
model: Rutherford- bohr model
Theory: electrons surround the nucleus in specific energy levels
5 metal properties
-solid (except mercury)
-shiny
-good conductors
-malleable
-ductile
5 non- metal properties
-solid, liquid, gas,
-dull (not shiny)
-poor conductors
-brittle
-not ductile
whats a period
horizontal rows
groups
vertical columns
4 chemical family
alkali
alkaline earth metals
halogens
nobel gases
standard atomic notation
-Write the element short form
-mass number on top
-protons on bottum
where are subatomic particles located
protons- nucleus
neutrons- nucleus
-electrons - orbitals around the nucleus
charge of subatomic particles
protons - positive
-neutrons- neutral
-electrons- negative
whats an isotope
atoms of the same element that have different numbers of neutrons
orbital trends
the period it is, determines how many orbitals the elemten has
atomic radius
the size of the atom
How many electrons fit in the first second and third orbital
1-2
2-8
3-8
Elements vs. Compounds:
Elements: A pure substance that cannot be broken down into simpler substances. ( hydrogen, sodium, oxygen, chlorine etc.)
Compounds: A pure substance that contains 2 or more different elements in a fixed ratio. ( salt, sugar, water, carbon dioxide etc.)
Atom vs. Element:
Elements are a pure substance and Atoms are the smallest units of elements
Why are atoms neutral?
Atoms contain the same number of protons and electrons making their overall charge always neutral.
what is Static Electricity
The buildup of an electric charge on the surface of an object.
Charging by conduction (contact):
when Two objects have a DIFFERENT charge