Atomic Model
1) An atom is made up of three types of sub-atomic particles - protons, neutrons and electrons.
2) Sub-atomic particles differ in mass and electric charge.
2) Sub-atomic particles differ in mass and electric charge.
3) Protons number, Z = number of protons
Neuclon number, A = number of protons and neutrons
Number of neutrons = A - Z
4) An atom is electrically neutral. This means that in an atom, the number of protons is equal to the number of electrons.
5) Isotopes are atoms of the same element with the same number of protons but different number of neutrons.
6) Isotopes have the same chemical properties but slightly different physical properties.
7) Electrons are arranged in electron shells.
8) The first electron shell can hold a maximum of two electrons. The second and third shells usually hold up to eight electrons.
9) The way in which electrons are arranged in electron shells are called the electronic structure / configuration of the atom.
10) Valence electrons are electrons found in the outer shell of an atom. They are important because they afect the chemical properties of an element.
(Refer to Manual Journal for more details and pictures of the set-ups)
Neuclon number, A = number of protons and neutrons
Number of neutrons = A - Z
4) An atom is electrically neutral. This means that in an atom, the number of protons is equal to the number of electrons.
5) Isotopes are atoms of the same element with the same number of protons but different number of neutrons.
6) Isotopes have the same chemical properties but slightly different physical properties.
7) Electrons are arranged in electron shells.
8) The first electron shell can hold a maximum of two electrons. The second and third shells usually hold up to eight electrons.
9) The way in which electrons are arranged in electron shells are called the electronic structure / configuration of the atom.
10) Valence electrons are electrons found in the outer shell of an atom. They are important because they afect the chemical properties of an element.
(Refer to Manual Journal for more details and pictures of the set-ups)