atoms. the basic building blocks of matter they make up everything found in the world around us. you...

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AtomsThe basic building blocks of matter They make up everything found in the world around us.You are even made up of atoms!Atoms are made up of three subatomic particles:ProtonsNeutronsElectronsEach of these particles carries a chargeTake a moment to think about what charge you believe each of these particles carry.

What are atoms?Protons carry a positive chargeNeutrons carry a neutral (no) chargeThe nucleus of the atom is made up of a mass of protons and neutronsProtons and Neutrons image3Carry a negative chargeCircle the nucleus forming the electron cloudVery small compared to the other parts of the atom and move so fast it is difficult to pinpoint their location


The number of protons and electrons in an atom are usually equalThis causes the atom to have a neutral (no) chargeWhat would happen if there were more electrons than protons? More protons that electrons?


The electrons in the outermost shell of an atom This shell is called the valence shellThe only electrons that react with other atomsValence Electrons out the copy of the periodic table and a pencilNumber the columns of the periodic table Not including the ten columns of the transition metals in the middle blockStarting from the left label the first column 1, the second column 2, the thirteenth column 3, the fourteenth column 4until you are to the right side of the table and you have labeled the eighteenth column 8How to find the valence electrons

*except He (it has 2 valence electrons) 1 2 3 4 5 6 7 8 * The number that you have put above the column represents the number of valence electrons of the elements in that columnThe only exception is He which only has two valence electrons but is located at the far right due to similarities in chemical behavior to that groupHow to find the valence electrons (C) Hydrogen (H)Oxygen (O)Nitrogen (N)Boron (B)Chlorine (Cl)Potassium (K)Strontium (Sr)Astatine (At)Neon (Ne)Bromine (Br)Sodium (Na)What is the number of valence electrons for the following atoms?AnswersCarbon (C) Hydrogen (H)Oxygen (O)Nitrogen (N)Boron (B)Chlorine (Cl)Potassium (K)Strontium (Sr)Astatine (At)Neon (Ne)Bromine (Br)Sodium (Na)What is the number of valence electrons for the following atoms?416537127871An atom in which the total number of electrons is not equal to the total number of protonsThe atom has a net positive or negative electrical chargeIon

Atomic number - number of electrons actually present in the atom = overall electrical charge of atomAtoms are happiest with full valence shells (8 electrons)They will interact with other atoms and gain or lose electrons to achieve this

Determining an Atoms Charge

Elements in groups 1 3 find it easiest to loose electrons and thus make positive ions or cationsElements in 5 7 find it easiest to gain electrons and thus make negative ions or anionsThe number of electrons gained or lost will determine the chargei.e. loss of 1 electrons = +1 charge

Determining an Atoms Charge

Using a periodic table determine what charge the following elements would likely have.NaAsBrSMgB

ExampleNa: +1As: -3Br: -2S: -1Mg: +2B: +3


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