Easy summary for Atomic Structure a level chemistry

Easy summary for Atomic Structure cameroon gce revision


Summary 
■ Every atom has an internal structure with a nucleus in the centre and the negatively charged electrons arranged in ‘shells’ outside the nucleus. 

■ Most of the mass of the atom is in the nucleus, which contains protons (positively charged) and neutrons (uncharged). 

■ Beams of protons and electrons are deflected by electric fields but neutrons are not. 

■ All atoms of the same element have the same number of protons. This is the proton number (Z), which is also called the atomic number. 

■ The nucleon number, which is also called the mass number (A), is the total number of protons and neutrons in an atom. 

■ The number of neutrons in an atom is found by subtracting the proton number from the nucleon number (A – Z). 

■ In a neutral atom, number of electrons = number of protons. When there are more protons than electrons, the atom becomes a positive ion. When there are more electrons than protons, a negatively charged ion is formed. 

■ Isotopes are atoms with the same atomic number but different nucleon numbers. They only differ in the number of neutrons they contain.

Comments