Flashcards
Atoms
Cards in this deck (7)
- 1What are atoms?Atoms are the smalles particles, everything is made of atoms.
- 2Structure of atomsAtoms are made of protons = positive charge, neutrons = neutral charge, electrons = negative charge.
- 3John Dalton's theoryOn 1893 Dalton proposed that atoms were a compact and firm sphere.
- 4Joseph ThompsonOn 1897 Thompson proposed that atoms were a proton sphere with positive charge and electrons embedded on it.
- 5Ernest RutherfordOn 1911 he proposed that electrons were in a permanent orbit.
- 6Niels BohrOn 1913, he proposed each atom had a nucleus and electrons around.
- 7Werner HeisenbergOn 1927, he proposed that mass was concentrated in the nucleus, with electrons in shells.
