Atomic Structure

+ve charged nucleus containing most of mass, surrounded by atomic shells with orbiting electrons containing negligible mass
Atomic/proton number gives no. of protons in nucleus; also defines the element and gives no. of electrons in an ATOM
No. of electrons is same as no. of protons in an ATOM, so atoms are electrically neutral
No. of electrons is different to no. of protons in an ION so charged: +ve = lost electrons, -ve = gained electrons; find original no. of electrons in atom (atomic no.) then add/subtract
ISOTOPES - ATOMS OF AN ELEMENT WITH DIFFERENT NUMBERS OF NEUTRONS AND DIFFERENT MASSES
Mass/nucleon number is no. of protons plus no. of neutrons. Find no. of neutrons by subtracting proton no. from mass no.
Different isotopes of same element react in same way - electrons involved in chemical reactions, not neutrons

Resource summary

	Created by lucy.wright73 over 10 years ago