Q1: Atoms

Ernest rutherford

gold foil experiment, atom is mostly empty space, predicted that there must be another particle present. He discovered the nucleus.

3 main components of atom

protons, neutrons, electrons

John Dalton

reconsiders "atoms", argues that elements are made up of small particles. Atoms of the same element are identical in size, mass, and other properties.

atomic number

the number of protons in the nucleus of an atom

JJ Thomson

discovered the electron, plum pudding model

isotope

An atom with the same number of protons and a different number of neutrons from other atoms of the same element.

Robert Brown

Brownian motion, random motion of particles suspended in fluid.

Niehls Bohr

Came up with the planetary model and energy levels of electrons. electrons orbit and can change orbit by releasing/ absorbing energy.

atomic mass

Number of protons and neutrons

ion

an atom that experiences an imbalance of charge. Protons= positive Electrons= negative