Presentation on theme: "IONS Big Idea Atoms can gain or lose electrons to form charged particles called IONS."— Presentation transcript:
IONS Big Idea Atoms can gain or lose electrons to form charged particles called IONS
Orbitals and Energy Levels Each electron in an atom has a definite amount of energy. Electrons in orbitals further from the nucleus have more energy. Orbitals that are FULL of electrons are most stable. Which electrons in this atom have the most energy?
What are Ions? Atoms are neutral particles because they have the same number of positive protons and negative electrons. An ion is a charged particle. An ion is formed when an atom gains or loses electrons.
Forming Ions Type of IonHow Formed?Example Negative Ion = anion Formed by gaining negative electrons F F -1 Positive Ion = cation Formed by losing negative electrons Na Na +1
Ions want noble gas orbitals! Noble gases have stable energy levels for their orbitals. Atoms want to form ions with the most stable energy levels. To form ions atoms in groups 1, 2, 13 will lose valence electrons. To form ions atoms in groups 15, 16, 17 will gain valence electrons.
Forming a Fluorine Anion 9p 10n Fluorine Ion has a -1 charge! Total charge in fluorine atom = +9 plus -9 = 0 Total charge in fluorine ion = +9 plus -10 = -1 Fluorine Atom (F) Atomic Number = 9 # protons = 9 # electrons = 9 # neutrons = 10 Atomic mass = 19 + + + ++ ++ + + F -1
Forming a Magnesium Cation The neutral magnesium atom Mg has Atomic mass=24 Atomic number=12 12 protons 12 neutrons 12 electrons Total charge on magnesium atom=0 A magnesium ion is formed by losing 2 valence electrons. 12p 12n This forms a cation, Mg +2
Pattern for Ionic Charges Group # 12131415161718 Gain or Loss of Electrons? Loss X Gain X How Many Electrons? 123X321X Ionic Charge? +1+2+3X-3-2X
Noble Gas Orbitals When the orbital contains a full set of electrons, the atom is said to have a stable noble gas orbital. First orbital : 2 electrons to be full (complete) Second orbital : 8 electrons to be full (complete) Third orbital : 8 electrons to be full (complete) Group 14 and 18 elements do NOT form ions!!!
Test Yourself What ion will calcium form? Ca +2 Will sulphur gain or lose electrons to form an ion? By losing electrons, so there are more positive protons left. Gain 2 electrons How is a cation formed?