Atoms, Molecules, and Ions Atomic Theory of Matter John Dalton – earliest version of the atomic theory 1. Elements are composed of small particles called atoms . 2. Atoms of a given element are identical 3. Law of Conservation of Matter/Energy – matter/energy cannot be created or destroyed 4. Two or more elements that combine chemically form compounds
26
Embed
Atoms, Molecules, and Ions Atomic Theory of Matter John Dalton – earliest version of the atomic theory 1.Elements are composed of small particles called.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Atoms, Molecules, and IonsAtomic Theory of Matter
John Dalton – earliest version of the atomic theory
1. Elements are composed of small particles called atoms.
2. Atoms of a given element are identical
3. Law of Conservation of Matter/Energy – matter/energy cannot be created or destroyed
4. Two or more elements that combine chemically form compounds
Atomic Theory of Matter
Element – one kind of atom
Compound – 2 or more elements chemically bonded. Chemically different than elements
Mixture – 2 or more substances together, each maintains its chemical identity
Discovery of Atomic StructureSimilar charges repel each otherOpposite charges attract each other
A. RadioactivityErnest Rutherford – 3 types of radiation
Alpha (α) – positively charged particle
Beta (β) – negatively charged particle
Gamma (γ) – no charge; dangerous
Alpha particle (α) is the core of a helium atom
Nuclear AtomJ.J. Thomson – atoms are a uniform positive
sphere with electrons embedded in it.
“Plum Pudding Model”
Nuclear AtomRutherford – fired alpha particles at gold foil
to study scattering, most went straight through, some bounced straight back.