chem final unit 2 Flashcards
Democritus
Democritus proposed that matter is composed of small, indivisible particles called atoms
dalton
(billiard ball) Introduced the idea of atomic mass: He showed that elements have different atomic weights.
thomspson
(plum pudding)Thomson is best known for discovering the electron, Thomson conducted experiments using a cathode ray tube,
cathode ray tube
To figure out the charge of an electron: If electrons had a + charge they would move towards the negative plate, etc.
Result: the beam of electrons moved towards the + plate, meaning they have a - charge
rutherford
(nuclear model)conducted the gold foil expierment and concluded The atom has a dense, positively charged center. The fact that some alpha particles were deflected or bounced back meant they had hit something small and dense in the center of the atom. Rutherford concluded that this was the nucleus
daltons atomic theroy
John Dalton’s atomic theory stated that all matter is made of indivisible atoms, and atoms of the same element are identical in mass and properties. Atoms combine in simple ratios to form compounds, and in chemical reactions, they are rearranged but not created or destroyed.
proton
Relative Charge: +1
Relative Mass: 1
charge and mass neutron
Relative Charge: 0
Relative Mass: 1
charge and mass of electron
Relative Charge: -1
mass: ~ 0
isotope
An isotope is a version of an element that has the same number of protons (so it’s the same element), but a different number of neutrons. This means isotopes of an element have the same atomic number but different atomic masses.
Carbon-12 (¹²C) has 6 protons and 6 neutrons.
Carbon-14 (¹⁴C) has 6 protons and 8 neutrons.
alpha radiation
4/2 He
beta radiation
0/-1
gamma radiation
0/0 &
decay
whole > particle + rest of whole
strong force
It is the force that holds the nucleus of an atom together, acting between protons and neutrons. acts over SMALL diferences
electrostatic force
It is the force that causes like charges to repel and opposite charges to attract.
fission
Fission is a nuclear reaction where a large, unstable atomic nucleus splits into two smaller nuclei, releasing a large amount of energy. an uncontrolled chain reaction emits the energy
fusion
Fusion is a nuclear reaction where two light atomic nuclei combine to form a heavier nucleus, releasing a tremendous amount of energy.
what is halflife
A half-life is the time it takes for half of the atoms in a sample of a radioactive substance to decay or transform into a different element. After one half-life, half of the original substance remains, and the other half has decayed.
how to calculate half life
- Identify the half-life
- Calculate how many half-lives have passed, years/hl
- Use the chart to track the amount of substance after each half-life.
nuclear reactor
A nuclear reactor is a device used to initiate and control a sustained nuclear chain reaction to produce energy. It takes the chain reaction to produce energy in a good way
parts of a nuclear reactor
- Fission in the fuel rods generates heat.
- The coolant absorbs this heat and carries it to the steam generator.
- The steam drives the turbine, generating electricity.
- The control rods regulate the reaction to maintain safe and steady energy production.
- The containment structure ensures safety by preventing radiation leakage.
atomic mass
larger number at the bottom EX: carbon is 12.01
how to find atomic mass
protons+ neutrons = mass number the isotope name tells you the mass number EX: carbon-14 mass number is 14
emits and alpha particle
elemnt > remainder + alpha
positron
0/+1 e
electron capture
element + 0/-1 e > new element
zeff equation
protons - VE = zeff
