Chapter 2 Flashcards
What was the law Antoine Lavoisier created?
The law of conservation of mass
Matter is Neither created nor destroyed
What is the law Joseph Proust made?
The law of definite proportions
All samples of a given compound have the same proportions of their constituent elements
What is the law John dalton made?
The law of multiple proportions
When two elements form two different compounds, the masses of element B that combine with 1 g of element A can be expressed as a ratio of small whole numbers
What are the 4 points of the atomic theory?
- All elements are composed of tiny indestructible particles called atoms
- All atoms of a given element have the same mass and are distinguishable from other elements
- Atoms combine in whole number ratios to form compounds
- Atoms of one element can not change into atoms of another element
What are cathode rays? What did they discover? Who’s responsible for this?
Produced when a high electrical voltage is applied between two electrodes within a glass tube
Discovered electrons
JJ Thompson
What is the oil drop experiment? What did it discover and who’s responsible?
Dropped oil onto plates by shooting them with ionizing radiation this discovered charge
Robert Millikan
What is radioactivity?
What are the three types?
The emission of small energetic particles from the core of certain unstable atoms
Alpha particles positive and most massive of the three
Beta particles
Gamma rays
What is the thin gold sheet experiments and what did it discover and by whom?
Ernest Rutherford shot alpha particles at a thin gold sheet and noticed some deflected back meaning there were clumps of positively charged particles called PROTONS
What are the three points of the nuclear theory of matter?
- Most of the atoms mass and all of its positive charge are contained in small core called nucleus
- Most of the volume of the atom is enmity space throughout electrons are dispersed
- There are as many negatively charged electrons outside the nucleus as there are positively charged particles within the nucleus
What is amu and how is it defined?
Atomic mass unit
1/12 the mass of a carbon atom containing six protons and six neutrons
What is the atomic number?
Mass number?
How is the chemical symbol written with these?
A#- The number of protons in an atom
M#- the sum of the neutrons and protons
M#
Element
A#
Or element-M#
What are isotopes?
Atoms with the same number of protons but different number of neutrons
What are the properties of metals?
Good conductors heat and electricity
Malleability (can be pumped into flat sheets)
Ductility (can be drawn into wires)
Shiny
Lose electrons when undergoing chemical changes
What are the properties of nonmetals?
Can be solid liquid or gas
Poor conductors of heat and electricity
Gain electrons when undergoing chemical changes
What are the properties of metalloids?
Semiconductors
