Chapter 02: Atoms and Elements Flashcards
Law of conservation of mass
Matter is neither created nor destroyed in a chemical reaction
Mass of reactants = mass of products
Law of definite proportions
All samples of a given compound have the same proportions of their constituent elements
Water is always H20
Law of multiple proportions
Atoms of two or more elements may combine in different ratios, producing various compounds
Subatomic particles
Election (e-) - negative charge, mass is minute
Proton (p) - positive charge, mass = 1840x an electron’s
Neutron (n) - neutral particle, GREATEST MASS
Cathode rays
Beam of particles, negatively charged
Cathode
Negatively charged electrode
Anode
Positively charged electrode
Radioactivity
Spontaneous emission of particles and/or radiation
Radioactive element
Spontaneously emits radiation
Alpha particles
Positively charged particles
Beta particles
Negatively charged particles
Gamma rays
Neutral charge, high-energy radiation
Nuclear theory
Nucleus = most of atom’s mass and all of its positive charge
Empty space = most of the atom
of protons = # of electrons, so atoms are neutral
Periodic table
Elements are in order of increasing atomic number
Row = period Column = group/family
Group 1A
Alkali metals
Group 2A
Alkaline earth metals
Groups XB
Transition metals
Groups XB - inserted rows
Inner transition metals