Unit 2 Test Review

All elements are composed of tiny indivisible particals called Atoms.

Atoms of the same elements are identical.

Atoms of different elements can physically mix together or can chemically combine with one another in simple whole-number ratios to form compounds.

Chemical reactions occur when atoms are separated, joined, or rearranged.

• -Cathrode Ray Tube.
• -Charge to mass ratio of the electron.

• -Gold Foil Experiment.
• -Positive charge localized in the atom.

• -Oil drop experiment.
• -Mass of the electron or the electron charge.

First periodic table. Arranging by Increasing Atomic Mass.

Perfected the periodic table. Arranging by Increasing Atomic Number.

• ^{Mass number} 33    
•                           P^{2-    Charge}       
•     Atomic #   15

• -Neutrons= Mass - Atomic #
• -Protons=Atomic#

               

• -High electricity and heat conductivity.
• -Metals are ductile and malleable.
• -Lose electrons in reactions.
• -Shiny(lustrous).
• -High melting point.
• -Corrosion, React Vigoriously with acids not bases, lose valence electrons to form ions when bonding, like to react with nonmentals.

• -Poor conductors of heat and electricity.
• -Solid nonmetals are brittle.
• -Little or no metallic luster(dull).
• -Most are gases at room temperature.
• -Low density.
• -Low melting point.
• -Not malleable or ductile.
• -Likes to react with metals,Gain Valence electrons to ions when bonding.

• -Siny or dull
• -Conductivity of heat and electricity better than nonmetals but not as good as metals.
• -Solid at room temperature.
• -Ductile and Malleable
• -Elements gain or lose electrons when bonding.

• 
• Group 7A

• 
• Group 8A

• 
• Groups in the middle(3-12)

• 
• The last two bottom rows

• 
• Group 1A-EXECPT Hydrogen

• 
• Group 2A

• (NA)(AMU)+(NA)(AMU)+(NA)(AMU)    =AMU
•                     100                            
• Natural ambundance=NA
• Atomic Mass Unit=AMU

Natural Ambundance times Atomic Mass Unit divided by 100 equals the AMU

• 
• Trend- Increasing down/Inceaising left

• 
• Trend-Increasing up/Increasing right
• -Decreses down a group because the valence electrons are farther from the nucleus and are held less tightly. Increases right because the atomic size decreses and valence electrons held more tightly.
• -Noble gases are stable and they don't react/ they don't want to form bonds/ not wnating to gain or lose and electron.
• 1^stionization energy is the energy required to remove the first electron.
• 2^ndionization energy is the energy required to remove the second electron.
• 3^rdionization energy is the energy required to remove the third electron.
• -You can tell what level of energy when looking on a table is the sudden spikes in number.

• -Anions are bigger than the atom from which they were formed because they gain and electron and increasing in size.
• -Cations are smaller then the atoms from which they were formed because they lose and elcetron becoming smaller in size.

• 
• -The tendancy of an atom to attract electrons to itself.
• -FONCL(phone call)-trend stops here
• -Noble gases have no elctronegativity do not want to gain electrons to form ions.
• -Elements with high electronegativty(nonmetals) tend to gain electron to form anions.
• -Elements with low electronegativty(metals)often lose electrons to form cations.

• -You can tell how many valence electrons by the group number.(the number with letter)EXECPT HELIUM.Each letter hold 2 electrons.
• -Convention(silicon/carbon)

• 
• _Match the number infront.Then count the expoents. then add it up.

• 
• S=2
• D=10
• P=6
• F=14

When it is a noble gas then go back to the other noble gas. Kr=[Ar]4s²3d¹⁰4p⁶

But when a reqgular element then just go back to the noble gas then start from there.