Atomic Structure

Protons, neutrons and electrons

-1 charge Whizz around nucleus in orbitals. Orbiter take up volume of atom

Most of mass of atom is concentrated in nucleus Diameter of nucleus of rather titchy compared to whole atom Nucleus where you find proteins and neutrons

1 mass +1 charge

1 mass 0 charge

1/2000 mass -1 charge

Number of protons, neutrons and electrons in an atom

Total number of protons and neutrons in nucleus

Atoms

Number of protons in nucleus it identifies the element All atoms of same element have same number of protons

The atomic number of the nuclear symbol because you don’t need it because the elements symbol tells you it’s value

Which have no overall charge the number of electrons is the same as the number of protons

The mass number minus the atomic number Top minus bottom in nuclear symbol

By gaining or losing electrons

Electrons than protons e.g. Br- Negative charge means 1 more electron than there are protons Br has 35 protons do Br- must have 36 electrons

Have fewer electrons than protons E.g. Mg2+ 2+ charge means 2 fewer electrons than there are protons Mg had 12 protons so Mg2+ must have 10 electrons

Isotopes of an element are atoms with same number of protons but different number of neutrons

Different number of neutrons

Are the same because both isotopes have 17 protons and 17 electrons

Atomic number of each element Other number by elements symbol in periodic table isn’t mass number through its relative atomic mass

John Dalton described atoms as solid spheres and said different spheres made up different elements

J.J Thomson discovered the electron. This showed stone weren’t solid and indivisible. Solid sphere idea of atomic structure had to be changed. New model known as “plum pudding model”

Ernest Rutherford and student Hand Geiger and Ernest Marsden conducted their famous gold foil experiment?

Fired positively charged alpha particles at a very thin sheet of gold.