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
What is a beta particle
Negatively or positively charged electrons
What are positrons
Positively charged electrons
What does the negative beta result from
The conversion of neutrons into a proton and an electron
What is the mass, atomic number and element/letter for negative beta
Mass-0
Atomic number- -1
Element- e
What does the positive beta particle result from
The conversion of a proton into an electron and a neutron
What is the mass, atomic number and element/letter for positive beta
Mass- 0
Atomic number- 1
Letter- e
What do you do with calculating negative beta
Proton goes up by 1
Mass stays same
What do you do when calculating negative beta
Proton decreases by 1
Mass stays the same
What happens when you calculate gamma
No change to nucleus
What are gamma particles
A type of electromagnetic radiation
Exactly like visible light but with a much higher energy and shorter wavelength, very damaging because it can penetrate tissue, organs and bones
What is half life
The time taken for half of the original number of radioactive atoms to decay
How to calculate half life
1/2 life mass (remaining)= original mass/# of 1/2 lives
What are properties of metals
Solid at room temp except Hg liquid
Shiny
Conductors (heat or electricity)
Malleable
Ductile
What are properties of non-metals
Solid,liquid, gas at room temp
Non conductors
Brittle solids
What are proper of alkali metals
Soft metals
Very reactive with water-not found in nature
React easily with halogens
What are properties of alkaline earth metals
Less reactive than group one
Often form oxides
What are properties of transition metals
Strong
Multitalented
Form many compounds
What are properties noble gases
Inent/unreactive
Outer orbit is full of electrons
What are properties of halogens
Very reactive with non metals
Easily react with hard alkali metals
