nucleus
protons and neutrons
relative mass: 1, relative charge: +1
mass: 1, charge: 0
mass: 1/2000, charge: -1
tells you the total number of protons and neutrons in the nucleus
number of protons in an nucleus which helps identify the element it is. all atoms of the same element have the same number of protons
electrons and protons
they have more electrons than protons
they have more protons than electrons
the ratio of the average mass of one atom of an element to one twelfth of the mass of an atom of carbon-12
elements that have the same number of protons but diff number or neutrons
yes, since the electron config decides the chem properties and isotopes have the same electron config
no, they have diff phys properties because the mass of the atom is diff eg diff densities or rates of diffusion
19th century he described atoms as solid spheres and said that diff spheres make up diff elements
in 1897, he discovered the plum pudding model which is when it was a solid postive charged sphere with negative electrons embedded in it
gold foil experiment: fired positive charged alpha particles at gold foil, most went straight through but some deflected back. proved plum pudding model wrong. rutherford made nuclear model
because the cloud of electrons idea would suggest that it would quicky spiral down into the nucleus making it collaspe. so neils bohr came up withe idea that electrons are in fixed orbitals.
electromagnetic radiation is emitted or absorbed
because not all electrons in a shell have the same energy. instead they made subshells
is the mass of an atom of an isotope of an element on a scale where an atom of carbon 12 is 12