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AtomsMoleculesElements

All matter is made up of particles (atoms and molecules)

Atoms

No, not The AtomsFamily!

These AtomsAtoms:The smallest particles of matter that can not be divided into smaller parts without changing their properties

Parts of an AtomParts of an Atom

Nucleus Center of an atom made up of protons and neutronsProton Subatomic particle with a positive chargeNeutron Subatomic particle with no chargeElectron Subatomic particle with a negative charge

Protons and neutrons have a much larger mass than an electron.Protons and neutrons are about 2000 times the mass of an electronButThey both have equally strong charges!

Hi there little guy!Who are you calling little? Im just as strong as you!

Proton/NeutronElectron

Electrons circle the nucleus in a fixed distanceOrbits - The path in which electrons move

Part of what holds an atom together is the attraction between the positive protons and the negative electronsor.

+-ElectronProton

Hi there little guy!Who are you calling little? Im just as strong as you!

Man, those electrons sure are negative!

Elements ElementsSubstances made up of only one kind of atom.Cats are not elements!

Elements Substance made up on only one kind of atomGold is an example There are more than 100 elements

Most elements are solid at room temperature Only a few are gas or liquid at room temperature

MoleculeMolecules are made up of 2 or more atoms joined together.

A moleculeis the smallest bit of a substance.

Many elementsoccur as molecules, not just 1 atom.

Most elements are metals and are solid at room temperature

Mercury and bromine are the only metals that are liquid at room temperature

A thermometerIs an example of liquid mercury

Metals have familiar properties:

Malleable can be hammered into thin sheetsDuctile can be formed into wiresConduct - can transfer electricityAlloys are mixtures of metal such as bronze or steel

Insulators conduct little or no electricity

Each element has an atomic numberFor example:

Hydrogen has only 1 proton in its nucleusSo it has an atomic number of 1Oxygen has 8 protons in its nucleusSo it has an atomic number of 8

Lets look at the Periodic Table to check out atomic numbers

No, not that table!Periodic TableGrouping of elements by similar propertiesArranged by atomic number

Invented in 1869 by Dmitri Mendeleev, a Russian chemist

Each column of elements are a part of a group (they often have same number of electrons in the outer energy levels of their atoms)Elements on the left side are metals (except for hydrogen)Elements on the far right are non-metalsElements with properties of both metals & nonmetals are metalloidsEvery element in the table is shown as an abbreviation known as the chemical symbol

Compounds substance formed when the atoms of 2 or more elements combine.When atoms join to form a compound, they go through a chemical change (the properties of the compound are different from the properties of the elements in it).Water is an example of a CompoundH20

Chemical FormulaShows which elements and how many atoms of each are in a compound.

Water H2O2 hydrogen atomsjoin1 oxygen atom

SaltNaCl1 sodium atomjoins1 chlorine atom

Sugar (glucose)C6H12O66 carbon atoms12 hydrogen atoms6 oxygen atoms

And, now for fun.a bit of triviaGuess how many molecules you weigh!

Amazingly, someone weighing 100 pounds, has about 916,778,800,000,000,000,000,000,000 molecules making up their body! I had to look it up how to say that huge number here. That's 916 septillion, 778 sextillion, 800 quintillion molecules in a 100 pound body!!

And RememberNever Trust an AtomThey make up everything!