A brief History Of Chemistry-Chapter 00 Flashcards
What are the 2 important ideas of Atomic Theory?
- Law of Definite Proportions
- Law of conservation of Mass
What does the Law of Definite Proportions Do?
-In a given compound, the elements are always combines in the same proportion by mass.
-You will always find 1g H to 8g O in water.
What does the Law of Conservation of Mass Do?
-No detectable gain or loss of mass occurs in Chemical reactions. Mass is conserved.
EXAMPLE—-> (If we have a closed vessel that contains 16g of O and @g of H and let them react, that vessel will contain 18f of water after the reaction completes.)
What is the atomic theory base on? What are atoms?
-Tiny submicroscopic particles
-Make up all chemical substances (which is everything)
-Smallest particle that has all properties of given element.
What are Dalton’s Atomic Theories?
- Matter(anything tangible) consists of atoms
- Atoms are indestructible
-In chemical reactions, atoms rearrange but do not break apart. - In any sample of a pure element, all atoms are identical.
- Atoms of different elements differ in mass and other properties.
- In a given compound, constituent atoms are always present in same fixed numerical ratio.
what does Cathode mean?
negative electrode.
What does Anode?
Who discovered the electron?
JJ Thompson (1987)
Who discovered the Atomic Nucleus?
Rutheford’s Alpha Scattering Experiment.
Where was the proton discovered?
Discovered in 1918 in Ernest Rutherford’s lab
Who discovered the Neutron
First postulated by Rutherford and coworkers also by James Chadwick
Define Attraction?
Attraction between protons and electrons
holds electrons around nucleus
Define Repulsion?
between electrons helps them spread out over volume
of atom
Isotopes?
Atoms of same element with different masses
Isoelectronic definition:
same number of electrons.
