inside an atom. the atom as a model structure of an atom atoms consist of protons, electron, and...
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Inside an AtomInside an Atom
The Atom As A ModelThe Atom As A Model
Structure of an AtomStructure of an Atom Atoms consist of protons, electron, Atoms consist of protons, electron,
and neutronsand neutrons Protons and neutrons make up the Protons and neutrons make up the
nucleusnucleus Protons: + chargeProtons: + charge Neutrons: neutralNeutrons: neutral
Electrons move around the nucleusElectrons move around the nucleus Electrons: (-) chargeElectrons: (-) charge They orbit the nucleus in energy levelsThey orbit the nucleus in energy levels # of protons and electrons are equal# of protons and electrons are equal
Structure of an AtomStructure of an Atom Atomic numberAtomic number
Number of protons in an elementNumber of protons in an element Hydrogen – Atomic number is 1Hydrogen – Atomic number is 1
Atomic massAtomic mass Amu – atomic mass unitAmu – atomic mass unit Total number of protons and neutrons in Total number of protons and neutrons in
an elementan element IsotopesIsotopes
Isotopes have the same number of protons Isotopes have the same number of protons but a different number of neutronsbut a different number of neutrons
Ex: carbon-12, carbon-13, and carbon-14Ex: carbon-12, carbon-13, and carbon-14
11
NaSodium
22.990
Problem
a.What is the atomic number?
b.What is the mass number?
c.How many electrons? Protons? Neutrons
Modern Periodic Modern Periodic ArrangementArrangement
Horizontal rows are called periodsHorizontal rows are called periods Vertical columns are called groups or Vertical columns are called groups or
families. families. These elements have similar propertiesThese elements have similar properties periodic table songperiodic table song
Electron SharingElectron Sharing
Covalent bond – a bond in which electrons Covalent bond – a bond in which electrons are shared between atoms to form are shared between atoms to form moleculesmolecules Both atoms will have 8 valence electronsBoth atoms will have 8 valence electrons
Ionic BondsIonic Bonds
An atom that has gained or lost an An atom that has gained or lost an electron is called an ionelectron is called an ion
Ions have an electrical chargeIons have an electrical charge
Ionic BondsIonic Bonds
What Happens When Chemicals React?
Some cool chemical reactions
Reaction of sodium and chlorine
Exothermic vs. EndothermicExothermic vs. Endothermic
Exothermic Exothermic reactions release reactions release heatheat Become warmerBecome warmer
Endothermic Endothermic reactions absorb reactions absorb heatheat Become coolerBecome cooler