History of atom, Inside atom, Isotopes, radioisotopes, describing the table Flashcards
What was Democritus main theory
Atomos (tiny particles)
Atoms are indivisible and indestructible
What was daltons main theory
Atomic theory from scientific experiments
- all matter is made of electrons
- atoms can’t be created or destroyed
- all atoms of same element are identical
- chemical reactions happen when atoms are rearranged
- compound =2 or more different atoms
(5 points)
What was JJ Thompson’s main finding
Atoms can be divided
Discovery of negatively charged particle (electron)
What was rutherfords main finding
Discovered positive “core” made of protons with the gold foil experiment
electrons orbit in empty space around the core
What was Bohrs main finding
Electrons travel in specific energy levels, not in between the levels
Electrons can jump up a level if given a “quantum” of energy
What are the five names of people to remember for history of the atom
Democritus
Dalton
JJ Thompson
Rutherford
Bohr
What are the three subatomic particles found in an atom, it’s charge and where it is found
Neutrons- neutral, nucleus
Protons- positive, nucleus (making nucleus positively charged)
Electrons- negative, on orbits
What is the atomic number
Number of protons
What is the mass number
Sum of protons and neutrons (nucleus)
Define isotopes
Atoms of an element with the same amount of protons but a different amount of neutrons
How do you calculate the average atomic mass
You put
Avg (element letters not in brackets) = mass(other number shown / 100) (same thing for them all) = calculation
Do isotopes all have the same mass
No
Define radioisotope
Atoms of unstable isotopes decay, emitting radiation as their nucleus changes making it known as radioisotope and are said to be radioactive
What is the mass, atomic number and element/letter of alpha particles
Mass-4
Atomic number-2
Element-He
What happen when you do calculations with alpha
Proton decreases by 2
Mass decreases by 4
