Chemistry- Unit Test Flashcards
What is the Particle Thoery of Matter?
- All matter is made of individual particles
- the particles are always moving- the higher the temperature, the faster they move
- Particles are attracted to each other
What are the properties of a solid? What do the particles do?
the particles jiggle in place because they cant overcome the forces of attraction
What are the properties of a liquid? What do the particles do?
the particles have enough energy to move past each other, but cant completely overcome the forces of attraction so stay in contact
What are the properties of a gas? What do the particles do?
the particles have enough energy to overcome the forces of attraction and move independantly
What model of the atom is this? Was it first, second, third or last? + breif description
Model: Dalton
First model of an atom
shows: atoms of different elements have different properties
What is Daltons theory of his model?
- all matter is made of small indivisable particles called atoms
- all the atoms of an element are identical in properties such as size and mass
- atoms of different elements have different properties
- atoms of different elements can combine in specific ways to form new substances
What is the reason for a new model AFTER DALTONS MODEL?
They found atoms could be made to give off electrons
What model of the atom is this? Was it first, second, third or last? + breif description
Model: Thompson
Second Model ofthe Atom
Shows: all atoms must have electrons and since the atom has no overall electric charge, the sphere must be positive with negative electrons in it.
What was Thompsons theory of his model?
- Through experimenting with electric currents in a glass tube, he reasoned that all atoms must have electrons and since the atom has no overall electric charge, the sphere must be positive with negative electrons in it
(chocolate chip muffin model)
What is the reason for a new model AFTER THOMPSON’S MODEL?
- the gold foil experiment
What model of the atom is this? Was it first, second, third or last?
Model: Rutherford
Third Model of the Atom
What is Rutherfords theory of his model?
- through the gold foil experiment he realized that most particles went straight through, but 1 in 10,000 bounced back because it had been deflected by something big and positively charged
- he found the NUCLEUS- it ha most of the atoms mass and was very small compared to the size of the whole atom
What was the reason for the new model AFTER RUTHERFORDS MODEL?
- each atom gives off specific colours of light when excited by heat or electricity by jumping through different energy levels
What model of the atom is this? Was it first, second, third or last?
Model: Bohr
Fourth Model of the Atom
What was Bohr’s theory with his model?
- electrons were in different energy levels and could jump between levels by gaining or losing energy
- there is a maximum number of electrons in each shell
What model of the atom is this? Was it first, second, third or last? + it’s theory
Model: Modern Quantum Model
Most Modern model of the atom
Theory:
- electrons exist in specific energy levels but as a cloud instead of tiny points
What did Rutherford do in his gold foil experiment?
He directed a stream of small dense particles from a radioactive source at a piece of gold foil only a few atoms thick
What did Rutherford expect to happen in his experiment?
He expected that the particles would go straight through the foil because Thompson’s model showed small light electrons in a positive matrix
What happened in Rutherfords gold foil experiment?
- he realized 1 in 10,000 bounced back because they must have hit something very small but very dense
- the new model shows the majority of the mass is concentrated in a small “nucleus” at the center with electrons surrounding it
What is the location, charge and atomic mass of a PROTON?
Location: Nucleus
Charge: +1 (positive)
Atomic Mass: 1 amu
What is the location, charge and atomic mass of a NEUTRON?
Loation: Nucleus
Charge: 0 (neutral)
Atomic Mass: 1amu
What is the location, charge and atomic mass of an ELECTRON?
Location: around the nucleus
Charge -1 (negative)
Atomic Mass: About equal to 0 amu
What is the atomic number?
Atomic Number = Number of Protons
(the number of protons is the atomic number)
What is the number of protons equal to?
Number of Protons = Number of Electrons